If someone has higher levels of fatigue, or is more susceptible to depression or anxiety after COVID (both symptoms of long COVID) - is it any consolation to them that 'it is all in their head'? It is still an effect that must be considered and that must be studied and treated.
Real long COVID - are there still viruses or virus fragments in the body? Is it a minor autoimmune condition? Is it due to damage that the virus did? Is severity of initial disease progression linked to severity of long COVID effects?
Placebo long COVID - To what extent are people susceptible to media influence when it comes to disease effects? Are people in blue states more likely to get it than those in red states? What can be done to assure people that there's nothing wrong with them?
Also, if they acknowledge it might all be in their head then any placebo/nocebo effects might in fact go away.
Just because something 'might all be in their head', or has a partly psychological cause does not mean that it is easy to treat or can be dismissed, or that it won't happen to you. It just means it needs to be treated with appropriate methods, e.g. therapy.
The bottom line is that long covid most definitely needs to be considered both when setting public policy, and when deciding on the risks everyone personally is willing to take. And we do not yet have enough data on the effects that vaccines have on long covid or on the risks of getting it.
I don't think it's a placebo so much as just typical persistent flu symptoms and people misattributing other problems to their COVID case.
Which is not to regurgitate the meme about covid just being the flu, but if your body is weak and fights off a problematic disease, its not crazy that it takes a long time to heal fully. My original point, poorly worded, was mostly that if you're reducing hospitalizations, you're going to reduce long covid. It's not a mysterious orthogonal effect.