Yup. English spelling is an absolute mess. If you have an interest in linguistics, it's fun and interesting to be able to tell the origin of a word by its endings (-ize likely being of Greek origin etc). And sometimes it helps you when you're trying to spell a word of which you know the origin. But in the vast majority of cases, no one cares about any of that.
Everyone who can read even a tiny bit of English can make sense of -ise and -ize endings, so it's not really an issue in that regard -- it doesn't change the meaning of words, and the difference is inaudible. Things like "through trough though dough doe doff tough" are far harder (tougher, one might even say) for non-natives, and fixing those kinds of messes is a lot less obvious.