Isn't "social distancing" the in-between strategy already? I was thinking of something similar today, when questioned whether to have a friend to my house. If I followed the strictest measures, I wouldn't. But then, if nobody did and we were essentially on self-quarantine mode, then the virus wouldn't spread at all or very, very, little and we would be hovering in small numbers for months, until next fall/winter, when it could get really risky again (presuming that weather has an influence, like with flu). So doesn't the social distancing strategy want some appreciable degree of transmission, high enough to get to herd immunity in a reasonable amount of time, but slow enough to avoid a hospital crisis? Are governments just relying on the idea that some people will ignore the suggestions, and we'll get a reasonable degree of transmission over time during social distancing?
What about the idea that claims without evidence can be dismissed without evidence?
Evidence for safety of vaccines? Billions of safe vaccinations in the past, widely accepted as safe, solid scientific basis, etc.
Evidence for your Uncle's claims?
The comments about raising your seat are spot-on. The ergonomics in your seated photo look way off. Your local bike store can get you fitted into a bike that's appropriate for your build and help you set the seat and handlebars. Can't promise that your knee troubles will go away, but there's a decent chance. Frankly, I've never heard about someone who has no problem with their knees while running, but has knee problems on a bike.
Good luck!