At the time when schooling started, 6 years old kids were not considered to need babysitting or daycare. They were to large extend able to move around the world independently. If they were not in school, they either did useful work for parents, in shops or played with other kids (or did mess on the streets).
The origin of kindergarten is daycare - for 4 years old playing in streets with literally zero adult supervision.
Not at all.
Mass schooling eas originally designed to teach the low-skilled to work on complicated machines in large factories.
Modern society demands both parents working, a single parent can no longer cover even the cost of housing for an entire family. As is has become so expensive.
Let alone medical expenses, hobbies, tutition etc.
tldr; Schools turned into daycare facilites when housing became so expesive that both parents must work full time.
This is the natural result when society is designed in some way to extract everything possible from every individual. Basic survival is monetized, promises are broken, in a race to the bottom.
Like it or not, schooling was originally designed as a daycare that teaches conformity and compliance.
The idea that we can change that by improving things at the margins is IMO ludicrous.