You'd prefer instead that there's a separate code point for every possible permutation of base characters and modifiers (like accents)? So would you add z̃ as

You'd prefer instead that there's a separate code point for every possible permutation of base characters and modifiers (like accents)? So would you add z̃ as a character even though it isn't actually used in any known languages, because a tilde is used over 12 other letters already, so you might as well make characters for all of them? Or would you skip it and only pick ones in known use...and then constantly update the tables every time you discover an obscure use of diacriticals? My understanding is that there are some languages / writing systems where the problem is far more challenging - the possible combination of different modifiers could result in millions of possible characters, many of which are plausible even though most aren't known to be used in practice. I think the reality is that human written language is extremely complex, and any attempt to simplify it too much will end up leaving out some languages.