What really is "verification" in that case? "The user is legally entitled to use this string of letters to designate themselves"?

The notability mark is useful: it means you're following basketball star Michael Jordan, which is probably what you meant. If you actually wanted to follow your brother-in-law Michael Jordan or a law professor Michael Jordan, there's really no simple binary mark that will help you separate them from each other. You'll have to do your research.

You can do also research on The Real Elon Musk Who Has Billions Of Dollars And Isn't Giving Any Of Them To You, and I honestly don't know if there's any way to help people who can't figure that out. But I could see Twitter at least wanting to try to help save people from themselves, because the bell curve has two tails.

Other than that... I'm not sure what any kind of verification really does. Maybe a dating app can help save you from wasting your time, because the whole point is that you're meeting strangers, some of whom will be bad people who get booted repeatedly. That's a completely different use case.