I completely agree that marking the end of the Roman Empire with the fall of Romulus Augustulus in 476 is not very meaningful. But there was a definite collapse

I completely agree that marking the end of the Roman Empire with the fall of Romulus Augustulus in 476 is not very meaningful. But there was a definite collapse of Roman civilization in the West, with a highly urbanized society with a sophisticated economy and an elaborate tax system funding public goods (infrastructure, the legal system, security) and a fair level of literacy being replaced by a largely de-urbanized, almost completely illiterate, and in many places de-monetized society. The collapse didn't happen instantly or at the same time everywhere, but it did take place roughly during the 5th Century, and would have been noticed by people who lived at the time. They might not have known right away that things would be different forever, but there were definite events along the way - the sack of Rome in 410, the failure of Majorian's attempts to reconquer critical territories of the Western Empire, and others. I mostly feel that there's been a trend in historiography to over-emphasize continuity, with the theory of the "transformation of the Roman Empire." It looks much less like a "transformation" of the Empire from one state into another, and much more like a civilizational collapse. I agree that why this collapse occurred is difficult to answer, but I find the argument that it didn't occur unconvincing.