Let me tell you OP, we used to do so much pre covid. My children didn't use nursery but they had swimming lessons and gymnastics lessons and play groups and music classes, and when that wasn't happening we went to cafes and museums and parks. Our days were so full, we'd be out of the house from breakfast til dinner and they saw so many other children.
When covid put us into our first lockdown that was all gone. We went from these long full days out of the house, to spending every minute in our postage stamp sized square of artificial grass garden - and we thought ourselves lucky we had that much. My then 3 year old regressed badly, he went back into nappies, started having more tantrums. All the development checks with the health visitor were cancelled. It sucked, my mental health suffered hugely. And I know that we had it no where near as hard as others, but it still really really sucked - and that was in the summer time!
This time around I made the choice to enroll my now 4 year old in nursery part time. I was very anxious about it but I'm so glad I did. Since starting he has finally toilet trained, his counting and reading has come on at lightning speed, and he's just happier. As soon as its practical I'm going to increase his hours, currently he's only doing 9. The break it gives us has let me spend more focused time on my now 2 year old as well, and she's developing much faster now.
My point is that it's easy as a child free person to say "if I had kids this is what I'd do, this is how I'd feel" but the truth is that you don't. None of us saw this coming, none of us knew in advance how we would be affected, and we're all just doing our best. There are all kinds of reasons that parents have judged nursery to be the best option for their children despite the risks from covid, and that includes people who don't need nursery for work purposes.