If long covid doesn't exist we have to have a new name for the people permanently damaged by the disease.

Long Covid isn't really a unique or specific thing. Many viral infections can cause post-viral fatigue syndrome in a subset of patients. This has been extensively studied since the 1980s but the exact mechanisms are still not really understood. There's nothing special about SARS-CoV-2 in this regard, just more patients infected during a relatively short period.

https://pubmed.ncbi.nlm.nih.gov/3063394/