I am somewhat skeptical about the long covid thing. Not that the disease doesn't exist of course, but of the relationship with covid specifically.
To put it simply, we all got in contact with covid at some point. Some were asymptomatic, some mistook it for a cold, and some were confirmed cases. Plus there are vaccines, that are said not to be as effective at preventing long covid than they are at preventing severe (accute) covid. Some even say the vaccine itself can cause long covid-like symptoms.
So how many of these case really "long covid" and not just a condition no one really took into account before a global pandemic affected us all in a relatively short amount of time. There are some conditions that are known to get triggered with any kind of infection (ex: EBV), or other kind of disturbances. Covid is one of them, but so is the flu, or anything else really.
And then, there were the lockdowns, raise of remote work and all the resulting social changes. People took some weight, others lost some, sleep patterns, eating habits, etc... have changed for many people. All these could be potential triggers for some condition that while not caused by the SARS-CoV-2 virus, is a result of the pandemic.
I say all that because of a personal experience. In late 2020, I got unwell, very unspecific symptoms which felt mostly psychosomatic, and it lingered for months, with ups and down, and a global trend towards improvement. When I talk about it, "long covid" is usually the first suggestion, and I would believe it, except I didn't get covid at the time. No contact, no symptom, PCR and IG tests negative, etc... it was before I got vaccinated. I finally ended up getting covid for (I think) the first time last year, and it was a typical, milder than average case, with none of the "unwell" symptoms resurfacing. I still don't know what happened to me, and why, though the lifestyle changes caused by the pandemic may have something to do with it. But had it happened after a covid infection, I am sure it would have been attributed to it.