At least in my dialect/accent of English
tl;dr once upon a time everyone spelled words guided only by vibes, then spelling was standardised-ish, then after that there was a great vowel shift where the now standard-ish spelling became less intuitive. add the linguistic influence from French and latin (sprinkle in some germanic & a pinch of skandinavian), add the power balance between classes favouring fancier words (the nobles ate pork, beef, poultry, the peasants tended to pigs, cows, chickens). add some more stuff and there you go! a “functional” language of Anglonic Britonic English!