There’s some evidence that most “long covid” symptoms (everything except loss of smell) in most people who claim to have it are not due to covid:

https://jamanetwork.com/journals/jama/fullarticle/2787741

Specifically, reporting long covid symptoms correlates with thinking you had covid, and not as much with actually having had covid.

Of course this doesn’t mean there aren’t some real severe cases out there, but it’s probably not nearly as widespread as it seems.