> I'm ready to accept compose keys are usable, but it clearly seems to encourage incorrect spelling when you use a language with a lot of accentuated characters in a sentence

I don't think it's at all clear, because most people don't have a compose key - only linux does that.

> vim. I really don't see myself fighting to remap my habits and workflows, given what I perceive as very few benefits switching layout would provide

Being able to use a default vim is very useful, and the default vim is qwerty-oriented. (It took me a long time to learn to use hjkl on Dvorak).