If countries such as France, Germany and England by the early medieval period did not have substantive knowledge of ancient technology and science, such as Rome's

There's the flaw in that argument. The Romans and the Greeks rarely studied architecture academically as a modern student might to. Education was largely vocational, through apprenticeships and on the job training. In provinces like Britannia, this could cause significant issues: according to Bede, when the Roman garrisons pulled out in 383 and 410, they took with them all the trained architects, meaning that there was nobody left to instruct the next generation; after all, it's not like they could pick up a textbook and teach themselves. The solution to this problem, however, was equally self evident: after the arrival of the Augustinian Mission in 597, the new Church simply brought in a number of Flemmish stonemasons and architects who in turn instructed a new generation of English masons.

A relative lack of stone construction was less a question of ability as it was resources and culture. The English were adept stone builders, but culturally chose to build in wood for the majority of contexts. We have very few remaining examples of Early Medieval English simply because so much of it was in a religious context and so subsequently replaced by Gothic architecture from the 13th century onwards, but the chancel of Canford Magna church and St Martin-on-the-Walls, Wareham are good examples of pre-Conquest stonemasonry, albeit ones which still bear the scars of the Reformation on their interiors. For the majority of the English, however, wood construction was easier, faster, cheaper and simply more culturally apt. Significant large-scale stone construction at the same pace as the Romans also required vast amount of slave labour that the sub-Roman states simply didn't have access to.

By the time that Gothic appears in the 13th Century, European stonemasons have had some 600 years of continuous practice to improve on Roman designs.