Errr ! i suffer from long covid , have done since December , extreme fatigue, insomnia, extreme pain in my joints, making it difficult to walk without waddling . As a result of the above ive muscle loss and lack of energy. Having previously been very fit and active, So it certainly does exist
im a self employed , builder . I go out to work everyday, physically working sometimes after 2 to 3 hours sleep. the most i get is 5 hrs, usually wake up from the pain in my joints , this has been going on since getting over covid in November.
Although i get your point about public service workers or indeed anyone who can get paid sick , it is a great vehicle for free loaders .