Again, it's pretty weird that you interpret this claim as downplaying the seriousness of covid. The health risks of loneliness and isolation are very well established, and they're generally considered very significant.

This is a good recent meta-analysis on the topic

If that's not your bag, this is a readable interview in Harvard Review by a researcher in the topic

This is the CDC on the subject

To suggest one thing is a greater risk than another is not to say either of them are not significant risks. I'm just saying if your solution to covid is to completely isolate yourself socially you may be introducing more risk than you would introduce by spending time socially with other humans.