It would be helpful to explain what DCO (Developer Certificate of Origin, terrible name!) and CLA (contributor license agreement) stand for. I managed to get the idea from context and google though it would have been nice to be explicit in the post.
The point about the balance of power and power dynamics involved is interesting. I think it applies more broadly as well. Are these really “agreements” when individuals have no ability to negotiate them? They seem more like playground rules.
You can fork the project and ONLY publish your contribution with the public license (i.e. GPL) instead of agreeing to also cede rights to the company.
One problem is discoverability. GitHub lists forks in an un-sort-able manner.
This obviously doesn't solve the problem generally, but I recently found an extension called lovely-forks[1], that automatically shows the most starred fork for every github repository.