Many of the reports about 4 day work weeks have been exaggerated as the reduction in hours was far less than suggested as the days were lengthened.
Some people already work 4 day work weeks, 4 on/3-4 off is not uncommon in some lines of work, in other professions it would be more than a struggle. We have some severe skill shortages in the UK and that's before getting into the shift work and gig economy that often makes it possible for many of us to work from home as we do.
Maybe eventually there will be a shift that could change work and education patterns significantly. Shifts take a lot of effort and support with a pinch of the right circumstances. Getting support takes more than just offering plans.
That's the thing - most of us can recognize our current systems have flaws and a lot of unneeded things, but whatever we come up with will also have flaws and unneeded things & many are cautious about making a major shift that could have more unintended consequences than we have now. The whole 'Devil you know' way of considering known risks vs unknown ones.
I mean, I went to school half days for my entire kindergarten year, I was 4 when I started. The rest of my time wasn't adventures, it was largely spent watching my mother's soap operas, helping tidy my grandparents' house or wandering around by myself. That was normal. No one expected parents to take their kids on adventures regularly back then. That had benefits and risks and there are some to the models being suggested.
She is finding it easier each day to go in and is one of the most social there.
Your descriptions sound similar to me DD2 when she began school at 11. The adjustment takes time and for some children it will always be a wobble. We still, over a year on, have a 'and what percentage are you on?' chat. It's never been 100%, but it's never been below 70% either.
Thing is, most kids don't get a choice and most parents don't have many options either - not with keeping food on the table. When people are already doing the best with what they've got, telling them they should want to do just that little bit more is a good way to lose support.
I'm surprised people don't want to be just that little bit more involved
People get involved in different ways when their kids go to school. Some read over the curriculum on the website so they can get resources, some get into the parent governor role, some arrange large donations for the school library, and so on - there are many ways to be involved that doesn't actually involve us being physically present with our child.