If we all wore $2 N95-equivalent masks, spread out 6 feet whenever convenient, did outside whatever can be done outside, and received a vaccine at (roughly) the same time, COVID19 would be gone.
The costs are huge because we made them huge.
We ignore COVID19 when case counts are low, giving it a chance to mutate and spread. We take extreme measures when hospitals start filling up, shutting down schools and businesses.
See Korea, China, Taiwan, etc. for examples of reasonable-cost ways to control COVID19.