A lot of the symptoms of “Long COVID” are exactly the same as depression and anxiety symptoms. Brain fog, fatigue, muscle weakness: anyone who has ever had depression knows what this is like. Of course there are a small number of people who had severe illness from COVID and had to be hospitalized, and the road to recovery for them is quite long, but most people claiming that they suffer from Long COVID are not the ones who were hospitalized.
The fact that there is no diagnostic test that tells you whether you have Long COVID or not leads me to believe that this is yet another hidden manifestation of mental illness. I feel sympathy for people going through this, but it’s wrong to expect the medical industry to come up with any solutions.