I think the Aristotelian (though I might have reached for Platonic) idea is that there is an "A" which is essential, and that you map many various "A"s to that one A - which results in weirdness when you leave the Latin-alphabet based languages.
(Arguably even in English we run into the fact that there is not one "A" - there are many "A"s that sound and act completely different, and we collapsed them into one representation.)
That's not how Unicode works, A Α and А are different characters (latin, greek, cyrillic).
Many times I have asked my Hungarian wife whether a sound is "a" or "a with an accent" (A vs Á), but they are different letters in Hungarian, not just variations of one as they are in Italian. We made a mess with "accent unification".
Which is always fun when you think that clearly nobody thinks of "o or o with a leg" (O vs Q).