This is exceptionally rare. The vast majority of people who develop anosmia regain their smell and taste. And yes, it does happen with other viruses.
> Maybe that can happen with a bad flu sometimes, but it seems way more common with covid.
The danger here is the distance between what it "seems" like, and what it actually is. If you're basing your judgment on media reports, you have to understand that you're not getting a balanced picture. The news media dwells on the most exceptional examples, and neglects the (many more) examples of people who have no serious side effects at all.
> It seems like there's some nerve damage resulting from the virus that we don't yet fully understand.
The current best evidence is that the loss of smell is not nerve damage, but infection of the epithelial cells surrounding the nerves in the nose.