Linguistics would teach that it is the orthography that is flawed. The English language has many vowel sounds, more than most languages. But as you demonstrate, the orthography "lumps" many of them together. Which, again, is why I think English orthography is awful.

There's a great article at Wikipedia, scroll down to the "Vowels" section: https://en.wikipedia.org/wiki/English_phonology

There's a link the the article above to this page, which I don't suggest viewing on your phone. It has a great effort to document vowels across dialects of English, scroll down again to the huge table: https://en.wikipedia.org/wiki/International_Phonetic_Alphabet_chart_for_English_dialects

Be careful, the linguistics "rabbit hole" is deep (but fascinating)!