> Unions by definition will increase the number of protections for workers and increase the costs of labor.
This is only true insofar as the market is inefficient.
Suppose you have a free market for car services (i.e. no taxi regulations or similar) and the drivers all get together and unionize. They demand higher wages and get them. The only way the company can pay higher wages is to raise prices, so they do, demand for car service is reduced, and some of those people lose their jobs.
Since they're no longer employed, the people laid off quit the union. Car Service Number Two shows up, has no contract with the first car service's union, pays the original lower wage to the people put out of work, and attracts customers by charging lower prices. That causes Car Service Number One to lose business and have to lay off more drivers who then go to work for Car Service Number Two, and so on until everyone is working for Car Service Number Two. If they then unionize again, Car Service Number Three appears to hire the workers laid off due to the higher wage ad infinitum.
Which is why unions don't work in competitive markets.
> the problem with the free market is that it has to optimize for infinite growth.
There is nothing that requires this. What it needs to optimize for is efficiency. If you're paying $50 then you have to charge >$50 and you lose business to the competitor who pays <$50 and then charges <$50. But at scale this isn't a problem -- when everything you buy costs less, it isn't a problem that you get paid less.
The problem now is regulatory costs and cost disease preventing the lower prices from actually happening in many cases. But you can't fix high regulatory compliance costs by increasing regulatory compliance costs.