Permissive licenses and fenced community
What if you permissively license software, but restrict access to scarce community resources around an open source project?
Public Goods are those that can't be depleted. The lines of code and even the compiled binary that make up open source software can be infinitely copied at zero marginal cost. No one loses anything if one more or 1,000 more people download the bits representing code.
Common Goods are those that can be depleted, that are finite. For open source software, this is people time. Time spent reading and responding to an issue, whether it's a bug report, a feature request, or even a contribution of new code. Updating dependencies and making a new release. Writing documentation. Chatting in a community chat space. All of this takes people time, and there are only so many maintainers on a project spending time doing these talks.
What if it was required to contribute: either by helping with these tasks – from code maintenance to community tasks, or by paying to support the project, so contributors could have their hours compensated. And more paid contributors could be brought on, with more external contributions.
Especially with modern open source software and the open nature of Github's public social spaces, we've completely normalized using up the scarce resource of maintainer time.