The problem there is getting the initial seed funding. Investors put money into companies because they want to have control over the company, and they can't do that with a cooperative. There is a systemic bias towards capitalist company structure because of that.
The reality clearly demonstrates that investors don't bother investing in coops. You've obviously never actually tried to get investors to invest in a coop.
If you ever try starting a coop you'll find out how hard it is to get investment in practice. It's kind of hilarious that you think nobody thought of these obvious things to try before you.