I don't know what the difference between "long Covid" and bog standard PVFS (with a side of some lung damage that takes a few months to recover for some) is... Post-viral fatigue isn't a new condition and has always been a risk after having a nasty bug.
I've mentioned before that I had a bug way back in I think 2017 that wasn't even that bad, but I had horrendous post-viral symptoms that went on for months.
And a Uni friend of mine took nearly 12 months to fully recover from the glandular fever he caught on Freshers Week. I used to like to knock his door in the early morning because for the first few hours every day his face was puffed up like a beach ball and I found it really funny, so it was a nice way to start the day. He looked like a chubby hamster

... Ahh good times.