1. The flu vaccine is a big part of why we don't worry about it anymore.
2. "Is Covid worse than the flu? Yes. Is it so bad that we should shut those things down? No." That opinion just isn't supported by scientists, epidemiologists, and now many republican politicians even. Right now all signs point to a 1% fatality rate (meaning for every 100 cases of covid 1 person dies). If we just let Covid run rampant in an effort to reach herd immunity without shutting things down, we would be looking at potentially 30,000,000 deaths. That would be a disaster unlike anything we've seen in our history. Shutting things down, wearing masks, and other preventative measures buys us time to get a vaccine and develop better treatments so we can avoid needless death.
3. I agree that there are lots of things we should also be focusing on! But, those items you mentioned aren't transmittable diseases like Covid-19.
4. I agree on wearing masks! In fact, let's mandate it!