How often do you think this happens? I am through and through an Android + Windows user and hate Apple for certain things but I do have to admit their design decisions are pretty solid most of the time.

It's not like you're learning a new language everyday. Nor losing your eyesight. Keep in mind that the life of a cellphone is anywhere between one and six years, for most tends to be around three (speculation). Isn't reason enough to make it a top priority for people to be able to access language / text size changes in their settings everyday.