No Stupid Questions

This requires capital to do and the traits that drive having capital in the first place under capitalism also drive making capitalist structures to get more capital. It takes acting against your interests in capitalism to make a co-op.

That said, as a group a bunch of people could invest equally and have a fair amount of capital, especially with access to business loans. The key problem here is accessing finance and legal structures. The structure of an LLC is not really ideal for a co-op as it assumes individual ownership not group ownership. This can be worked through in a few ways but it is always a workaround, just something to make it work in the current system. The ideal would be some sort of shared, maybe creative commons, legal frameworks written up and cross checked by a bunch of lawyers. I think it could be done and very successful, but making that structure would require input from a bunch of people with experience with co-op structures. That said, once it is done they can all benefit for future endeavours and so can anyone else.

The other issue is culture. The USA has a culture of avoiding interdependence and being very individualistic. This is great for atomising workers and preventing unions, so it is encouraged from all capitalist sources including western media such as film and TV but also in things like which books are published and which are passed on. Nobody wants to produce media that will result in their own loss of financial wellbeing or status. Finding a way of shifting the culture is definitely a hard and currently unsolved problem.

There's lots and lots of low level community support, bartering and exchange. But once a good natured soul tries to organise that into something... taxes!

In short, co-ops are the closest socialist/communist business model that’s actually implemented in the U.S., so why are more leftists not doing this?

Starting a business (that is based on a sound and viable business plan that has even a snowball's chance of surviving its formative early years) is really REALLY hard. It takes massive amounts of money or debt, the early years promise years of having no income for yourself (or paying yourself below minimum wage), it means a staggering amount of hours you need to put in to keep it going, forgoing vacations and important family events, loss of friendships because you're having to put all your time and energy into the business without socializing, having to work when you're incredibly ill, incredible amounts of stress (which increases by 10 times when you have employees that now depend on you for their livelihood) and even if you do everything perfect your business can fail leaving you with nothing for the years that you put into it, and potentially also with tens of thousands or millions of dollars in debt. It means many times being force to make decisions that massively affect other people's lives (your employees or your customers). It can be versions of the Trolley Problem time and time again.

"According to the U.S. Bureau of Labor Statistics (BLS), approximately 20% of new businesses fail during the first two years of being open, 45% during the first five years, and 65% during the first 10 years. Only 25% of new businesses make it to 15 years or more." source

So ask yourself if you want to go through all of that, and instead of wealth you can live on and support your family with at the end of it, you get simply a "thank you" for building a co-op.

Poor communities already do this to support each other. They watch each other's kids. They run errands for each other. They don't keep track and charge cash and create an LLC. But community support is real.

Unknown! Profit share is something I've done with my own business and feel like it produces better outcomes for everyone (we measure our impact on customers, employees, owners, the business and community to make sure we are serving all of them). I'm looking into actually granting shares, so it is more real for the employees. Maybe other owners don't do it because it does require some amount of effort and transparency into company performance. IMO, owners can be really lazy.

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.

Because he who controls the capital, controls the legal structures of capitalism.

Aka pedons ain't got no money, boy

Because corporations will sweep in and take all the business by taking a loss just long enough to put the others out of business.

The kind of people who would start a business (to enrich themselves) and the kind of people who value co-ops and employee-owned businesses (to enrich others) does not have much overlap. I love the idea of coops, but I do not have the skills or ambition to start any kind of business.