Many reports of survivors having major organ damage after leaving ICU. After being on a ventilator for that long with reduced tidal flow of O2 and high levels of blood CO2, there has to be lingering or permanent side effects.
The lucky ones with no or small symptoms are not discussed scientifically as far as I know - the resources are spent on serious cases.
And what was it 20% of cases needing ICU/ventilators? That’s a crazy number. We simply don’t have that kind of capacity AND handle normal load.