Most of the ones that can cause disease in Humans haven't (gone away). We've just learned to live with them.I don't know my coronavirus history, but how did the previous ones go away? they just weren't as contagious?
The deadliest one, SARS, was similarly contagious to the current one, but it was so much more virulent that it was contained and eventually burned out.
MERS (can I still call it that or does that make me "racist?") still pops up from time to time but is easier to contain. It is not very contagious.