It seems so scary to ship software where you are not in full control over font rendering, because at that point you have suddenly have a million edge cases which you weren't forced to think about up front, but which can come back and bite you any time.
Though I guess with everything running in web browsers it sort of has become the only way to go.
Seems like this person found some new ones. Curious if they will ban them.
0: https://emptycharacter.com/