In other words, it’s turning into just another coronavirus.
Just as some predicted, the new mutations are milder, so the virus has a better chance of surviving and spreading.
Well, in most cases people die when the COVID virus is past its peak infectious period. Usually they die of complications. This still leaves a trend as you say, BUT, it is possible for enhanced severity to arise from a “weakened” previously strain, and retain high infectiousness. This is how some nasty versions of flu arise.
In fact, H1N1 A (Spanish Flu) may well have re-emerged in the last couple decades as H1N1 A (Swine Flu) at least as deadly without treatment as the Spanish Flu. But, we have much better treatments now, the social situation is different (no World War going on), etc. Even so, swine flu damn well nearly killed my brother.