Maybe people won’t become billionaires doing this,

I think the first bit is a big part. Keeping generated wealth is a main selling point for capitalism.

but why wait for a complete overhaul of society to implement more of what are good ideas … I’d also like to see more childcare co-ops, or community shared pre-k schools.

I think this is one part lack of resources. Those who can spare the most for a pool don’t see the need too. Those who need these things the most are still inside a market that does not reward such things. You would need way more low income people to fund the preK and the staff could do better working somewhere else, unless there is an element of altruism to working with low income communities.

A lot of things are market driven in the US and markets are not as good at selecting good ideas as our myths around them suggest. Right to repair is a good example of this. Everyone is better of being able to fix stuff; even if most chose not to. More people would be better with community this or that, but most people do not know about them, or they won’t know how to organize.

It is going to be hard to pick a pragmatic approach that can survive pressures from a for profit market that might have and that people will culturally accept today.