You don't even use them consistently in the same sentence (your unaccented i has at least 3 different values, for instance).

The real reason English spelling is frozen in the 1600s is that that is the last time all English speakers had a common language community. Since the foundation of the colonies, Englishes have diverged from each other from that starting point, so that no reform can be neutral to all current Englishes - some have merged what was distinct in early modern English (e.g. cot-caught merger); while in other cases what was a single class has been split (e.g. the bath-trap split). Wikipedia has a (non-comprehensive) table: https://en.wikipedia.org/wiki/Sound_correspondences_between_... note for example that even where two varieties have merged phonemes, they might have merged them differently (compare Southern American to Australian). You might try to come up with a spelling system that covers all possible combinations, but it would be then very hard for the speakers who have mergers (i.e. all of them) to use - how is an Australian supposed to know which äː vowels are æ in American and which are ɑ? How are the Americans supposed to know which ɑ's are äː vs ɒ in Australia? etc. etc.

It's very important for English to have 9000 vowels so we can tell where you're from within about a five mile radius, no matter how hard you try to hide it.

If you mess up every vowel in an English sentence, everybody can understand every word, but it makes everybody a little upset and a little aggressive. If you want to play it safe, just make every vowel a schwa and people will think you're from New Zealand.

Czech diacritics taking over the world :-)

You'd be surprised! I actually see a fair amount of haceks hereabouts in PNW because they are used in the orthography of the local Salish Native American languages, so you end up with road signs like these: https://www.charkoosta.com/news/salish-language-stop-signs-e...