The villagers hitbox is not like normal villagers hitbox, it is massively too big.

Incidentally, it is bigger than a minecart, making it impossible to get the villager out of a minecart.

(Of course it also makes it impossible for them to pass through doors; they asphyxiate easily, make it difficult to enter a boat already containing a villager, and also very easily for them to enter a boat or minecart).