From what I can tell looking at friends and family, a lot of people are currently returning from vacation, and it's been on the news a couple times that those people are bringing back covid, presumably visiting bars and clubs depending on where they traveled, easing the spread.

That would explain why it's becoming less deadly. The old and vulnerable don't travel, so we have a disproportionate amount of young people getting infected which recover well. Let's see how many of those who return can't resist visiting their grandparents in the first two weeks after returning. Maybe we get a delayed deadly wave when it hits the retirement homes again.