I believe the lockdowns, the collective trauma of having mass death happen around you and everyone acting like it's normal, and long covid, have made large amounts of people forget how to behave in public at all. Or at least care about anyone other than themselves. It used to be that people treating service or retail workers horribly was rare enough to become a meme, now it's business as usual. Same with public transportation and other shared spaces where everyone seems to just be their worst possible selves, or completely self-absorbed.