With the exception of the deep Maritimes, in particular Newfoundland, Anglophone Canadians pretty much sound the same with the exception of those with an immigrant background. As far as I know there aren't really any anglophone Canadian accents.
This is not the case in the US where you have distinct accents(southern variations, New Englander-Northeastern, Midwest). And then you have the UK with many accents in a relatively small area. France has also noticeable differences in France with people from the north, from the Ile de France and from the south sounding different to some extent.
Why doesn't the same exist in anglophone Canada?
There is regional variation in Canadian English beyond the (significant) examples you've listed.
So, first of all it's important to note that rural and northern areas of Canada are linguistically under-researched. The best-researched communities in Canada from a linguistics standpoint are Vancouver, Ottawa, St. John's, Montreal, and Toronto. Linguistic studies have also tended to focus overwhelmingly on the middle class. This lack of research on other populations in Canada has led to the common belief (including among linguists) that Anglophone Canada is linguistically homogenous. Historically, since the field began in earnest in the 1950s, Canadian linguists have been keen to demonstrate the differences between Canadian English and American English as a way of asserting Canada's linguistic autonomy. But this quest for a distinct national linguistic identity has often come at the expense of investigating Canada's own internal linguistic divisions. The main exception is Newfoundland English, which has always been recognised as distinct due to its relative lack of influence from American English.
Linguistic discourse in Canada has therefore traditionally been focused on defining Canada's autonomy in relation to American and British English, as well as on English-French relations. However, in the past few decades there has been increasing interest among linguistic researchers in documenting Canada's internal Anglophone diversity beyond just Newfoundland English varieties. This coincides with a decline in enthusiasm for Canadian nationalism at the end of the 20th century. The idea that Canada had a uniform dialect to which all immigrant dialects would eventually assimilate was popularized in the late nineteenth century. The image of a linguistically homogenous Canada gained traction in the first half of the 20th century. For example, Morton W. Bloomfield influentially wrote in 1948 that "one type of English is spread over Canada's 3000-mile populated belt". Commentators frequently compared Canada's imagined homogeneity of language to what they saw as the more linguistically diverse populations of the United States and England.
Like "General American" (known today as Standard American English), the concept of a "General Canadian" language was the product of an interest in nationalist standardization across Canada's empire (Canada being, of course, composed of large swathes of unceded Indigenous territory that are illegally occupied). The vast land mass of Canada was frequently invoked in triumphant claims about General Canadian's uniformity. However, these early proponents of Canada's linguistic homogeneity could only make their arguments work by excluding parts of Canada, and they did not all agree on which parts were different enough to be considered exceptions (with, for example, British Columbia sometimes being included and sometimes not, and with the Arctic rarely being taken into consideration). And again, these analyses only took into account the speech patterns of the middle class - as recently as 2008, the linguist Boberg defined Standard Canadian English as "the speech of middle-class people from Vancouver to Halifax". Chambers in 1998 defines the "standard accent" of Canada as "urban, middle-class English as spoken by people who have been urban, middle-class, anglophone Canadians for two generations or more" - criteria which include only 36% of the Canadian population. The Atlas of North American English divided Canada into three linguistic zones - British Columbia, Inland Canada (Prairies, Ontario, Quebec), and Atlantic Canada - but it based its findings on interviews with only thirty-five participants.
In fact, there is plenty of regional diversity in Canadian English. While the two obvious examples are Newfoundland and Quebec, both of which have long been recognised for having distinct varieties of English, there are other regions which show variety in accent and dialect. Some studies have been done on more unusual dialect enclaves like Lunenburg, Nova Scotia; the Bungee vernacular dialect of the Red River Settlement in Manitoba; and the dialect of Black "old-line" Nova Scotians. Less commented upon has been the phonetic and vocabulary distinctiveness of the Prairies, Western Canada, and the North. Many people who live in these regions are not middle-class or urban, and so their dialects have been under-studied.
A few examples of regional variety in Canadian English:
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