[bamfly]

People who've seen YouTube written down a couple times tend not to get it wrong. Twitter is a common dictionary word and I'd bet had a pretty low misspelling rate, if you'd asked people to spell it before the service Twitter even existed. TikTok, I think most people get after seeing it a few times, at worst.

Mastodon? It's a dictionary word, so it as that going for it—and yet, people see it a hundred times and still often misspell it. The pronunciation's just a bit too far from the spelling, at least in American English. Most folks say it as if it were spelt "mastadon", especially if they're not trying to enunciate carefully & precisely and (perhaps) don't know the correct spelling.

(I'm not weighing in on whether that's some kind of serious problem for Mastodon, but I do think it's worse than all your other examples, as far as likelihood of misspelling even after significant exposure—then again, web search smooths over most of that, for anything sufficiently popular)