There are plenty of studies about the long term damage that even a mild infection can have. Vascular damage causing strokes, brain damage causing brain fog and eventually dementia, immune damage causing increases in other illnesses that aren’t fought off like they used to be, etc etc. So cold level symptoms give the impression it’s fine and nothing but that’s just some symptoms of immune response.
Less severe at first maybe but plenty of studies showing long term damage from what starts as a mild cold. If reporting was being done on the science, that’s what it would say but reporting is very very limited.