So breaking down the long term ramifications of the Norman Conquest is a huge task, well beyond the reach of a Reddit answer, no matter how many parts to this I would be able to attach. But your question is still a good one, England had been something of a cross roads for the North Sea world stretching back to Antiquity with Roman, Celtic, Germanic, and a smattering of others, all providing different elements to life in the British isles afterwards.

But what it seems to me that you're asking is why was the Norman Conquest so impactful in the long run, and that is a slightly easier answer than detailing every single thing that did end up changing. It comes down to two things in particular, the long term political realignment of England away from Scandinavia and towards France and the radical restructuring of political life within England itself.

Let's break these down one at a time.

Up until the Norman Conquest England was not really a part of Western Europe so much as it was an offshoot of the Scandinavian/North Sea world. Dating back to the collapse of long distance trade that accompanied the end of the Empire in North Western Europe, England was plugged into the trade networks that operated around the North Sea. In turn it was more affected by the goings on in Scandinavia and Frisia (modern day Low Countries) than it was with the events that transpired in Francia. Now this is not to say that there was no influence from the continent at all pre-Norman Conquest, the area of Kent in particular held close ties to Francia before England was ever united, this is seen in both the material culture of the area which shows that Frankish goods made their way into Southern England, as well as through political developments, as seen by the marriage between a Frankish princess and King Aethelberht of Kent, eventually leading to his conversion to Christianity.

Small scale trade between Francia and England aside, the connections between England and Scandinavia were far more robust. This too has left evidence in the material culture of parts of England, for example East Anglia had close ties with Sweden based on the patterns of artistic depictions, armor, and potentially even surviving literature (The epic Beowulf recounts deeds in Sweden and Denmark that was probably composed in East Anglia). These economic and political ties set the stage for England in the early Middle Ages even before the Norse depredations.

The Scandinavian influence on England reinforced these economic patterns with political links. Scandinavian rulers began exerting power over England, drawing it firmly into the Scandinavian world that stretched from the New World on one extreme to the Caspian Sea at the other. England was at first able to resist the depredations of the Norse, to an extent, and despite the collapse of kingdoms such as Northumbria and East Anglia, eventually England was united under Wessex (and Mercia) and the Norse "Danelaw" was brought into England itself....except not really.

There is a great deal of surviving evidence that shows that the Danelaw continued to receive recognition for its different legal traditions and political situation long after it was absorbed into England. Nor did Scandinavian influence end there. The kings of Denmark (and one king of Norway) were not content to let England slip from their sphere of influence and the 11th century saw immense conflict between England and the Danes who successfully conquered England twice in the time frame, reinforcing England as a part of the North Sea world, particularly under Canute the Great. These ties also cut both ways, as England became an economic, political, and cultural powerhouse under the rule of Canute and was deeply involved in the conversion of Scandinavia to Christianity through the involvement of the English church.

It was only with the collapse of Canute's dynasty a few years after his death that England was once again able to achieve independent rule, however this was the start of its reorientation.

The, eventual, heir to Canute in England was Edward the Confessor, who had spent much of his youth in exile for fear of his life from Canute, and a great deal of that time was spent in Normandy. Following his ascent to the throne, according to Norman sources (so grain of salt and all that), he heavily favored the advancement and promotion of Normans at court as well as within the Church. William the Bastard's claim to the throne was not as ridiculous as it may seem as he was connected to Edward's family through marriage, and that was just the tip of the iceberg for the increased ties between Normandy and England.

Following his successful invasion of England William could not rest easy however, and he had to see off Danish incursions onto England that, had they gone a different way, may have wrested control of the island once more into the hands of Scandinavians. However it is worth mentioning that our textual sources are not clear on the size and scope of the Danish involvement. One source claims that it was a fully fledged invasion force that aimed to place a different claimant on the throne, but another characterizes it as more of a glorified raiding party. But with the failure of the Danish expedition, regardless of its size and intent, England was sundered from the Scandinavian world.

This was further reinforced by the second major point, the political restructuring of England following the conquest. Here the key moment is not 1066 and the Battle of Hastings as you might assume. While this battle did wreck the power of Harold Godwinson and his brothers (killing many of them) and placed all of southern England under Norman control, it was not until the 1070's that effective Norman control over all of England was established, and this was a result of the "Harrying of the North", wherein William waged a brutal, even by medieval standards, counter insurgency against rebellions Anglo-Saxon lords. Only following these campaigns in the mid 1070's was all of England firmly under the control of Normans.

This collapse of the pre-conquest elite, through the double whammy of Hastings and the Harrying of the North, not to mention the failed uprisings that variously had Harold Godwinson's sons at their head, Edward the Confessor's closest male relative, Danes, Scots, and lords of western England, all trying to usurp Norman power, left a massive political vacuum in England, and this was filled through the Norman importation of lords and minor land holders to rule and administer the lands of England that formally belonged to the king. This is often described at the importation of Feudalism into England and it is not quite that simple, but the stage was set for the political restructuring of England. The large landholders that characterized the pre-Conquest political landscape of England were gone, and in their place were much less powerful individuals and families with divided holdings.

When this was combined with the extremely well developed administrative structure of England, for the time, this led to the creation of a powerful monarchy in England with extensive financial capabilities. Indeed, this was likely William's main motivation for conquest. William himself never really bothered to rule England as an English king and seems to have placed greater emphasis on his status as Duke of Normandy, for example this is the title that he passed to his eldest son, whereas England was more or less a giant tax generating machine that could be used to finance the conflicts in France between Normandy and the rest of the country.

The changes that you mention such as linguistic change and cultural changes were not necessarily intended by William, and were indeed long to develop. It was not until the ascent of the Angevin kings to the kingship that England really was able to operate as an independent entity, not just an offshoot of the Norman duchy, and the legal, cultural, and economic changes of the high Middle Ages all postdate that later development. Indeed, it is possible, if we are to engage in a little speculation, that a successful rebellion against William might have re-oriented England back to Scandinavia, but that is a story to be told by alt-history fans.