Why is there no community-led version of UpWork / TopTal marketplace?

UpWork, Freelancer, TopTal or any other freelance marketplace are inherently predatory - their goal is to maximize value extraction and lock in both employers and freelancers. They get to the top of the competition and charge us 10%-20% fee that they spend mostly on marketing to stay on top. The combined capability of the freelance community is several degrees of magnitude more than what any of those business have. What would it take to organize and build a community-centric marketplace that maximizes delivering value and only charges what is needed to sustain itself? Anyone wants to join me on this quest?