Yeah they aren't unheard of at all, co-ops have had slow but steady growth in the market for some decades now.

I’m not sure I follow. In what market(s)?

One famous example is Igalia, doing Open Source consulting for various companies, including Google, Apple, and others.

They're a worker owned co-op and have grown very nicely over the years.

Igalia are very cool! Not sure if it’s so easy to reproduce their success (if I’m wrong on that point, that’s only good I guess).

Agriculture has a lot, utility services including fiber internet, electrical, and natural gas, many credit unions, there are a few retail stores like REI, mutual insurances, a number of pharmacies and homecare and other health services are co-op, many other worker co-ops, and there are a decent number of housing co-ops. Other than maybe a few rural fiber co-ops most are not super fast growing businesses, and they lack attention seeking rich owners, so they don't get a lot of attention, but co-ops as a whole has steadily gained more market presence nearly across the board over the decades.

Cool!