That is true, but flu (I mean real flu, not the pathetic little sniffles that many people call flu) is a far more serious illness than covid.
Flu is potentially fatal for all age groups, but especially the elderly and very young children. Post viral fatigue, after recovery from the acute illness, is common after an episode of flu.
Covid is a greater concern than flu, because we have had much longer to manage flu with vaccination and natural immunity than we have had with covid. Flu also has a narrow and predicable season from early December to the end of February in the UK. Any illness outside these months is unlikely to be real flu. Covid is likely to strike any time.
Anyone who is suffering from real flu would be unlikely to leave home, even if they wanted to, because it is debilitating for at least a week and often more than two weeks. This, combined with the fact that it is not as transmissible as covid, means (thankfully) you are not very likely to catch it unless we have a serious epidemic.
Covid isn't flu. It is more like the kind of colds caused by the other corona viruses we are more used to.
Covid is a concern to society due to its transmissible and unpredictable nature and the fact that it is still potentially fatal. Flu affects far fewer people (unless we have an epidemic which could potentially happen any time), but is a more serious illness.
I never like being ill, but given the choice (I have had flu once about 30 years ago and covid twice), I would rather have covid than flu.