It will be annoying if bank sites and other companies that are hard to avoid drop Firefox support (I mean I can switch banks I guess but it is a long term customer relationship, I don’t really want to).

Most websites aren’t bank websites. If a website doesn’t support Firefox, leave. If a website doesn’t support good old HTML, it is probably made by some kind of dummy who is trying to replace lack of content with glitz, this sort of person shouldn’t be listened to.