Some variation of the anthropic principle maybe comes into play here. If it had more deleterious effects, we may not be here to make these observations.

It's nr 2 variant is a lot less pleasant apparently, not to mention how it would affect dating prospects and such, so it's rather sad that science has no solution for these and many other viruses. What I don't understand as a lay person is the extremely slow rate of progress against viruses like these - imagine computing as a field progressed as slowly as this...

100mg quercetin 100mg egcg (green tea) 100mg cinnamon extract

Boost your immune system and metabolism and these viruses never activate. Reducing inflammation and oxidative stress is the most easily accessible method for controlling viral outbreaks

This works for the whole spectrum of incurable viral infections