@mike As much as I would like to agree with the message that we need to free our commons, I fail to see how this applies to software.
The concept of privatisation only makes sense for resources to which access can be restricted, typically physical resources like potable water from a lake. This is not the case of open source software: once it has been distributed, everyone can freely copy, study/modify (assuming minimum skill/knowledge) and redistribute it, for virtually no cost (assuming minimum infrastructure, i.e. personal computer and internet connection).
Big software companies did not privatise existing OSS or infrastructure, they created their own proprietary solutions and platforms partly using the latter, and managed to make almost everyone use those. And then they also started privatising users' data produced within these solutions, which is one of the main causes for vendor lock-in and enshittification.
The question is: how did these companies manage to attract all the users? I think it has nothing to do with software licences. The reality is that because they participated in the capitalist economy (which isn't really possible with copyleft), they had more physical/human resources they could invest in both 1. designing better software, in the sense of being easier and more practical to use for the average person with no technical knowledge; 2. marketing the software, so that people are aware of its existence (regardless of its actual quality); 3. growing centralised infrastructure to keep the software and data both alive and privatised, at scale.
It is very hard to imagine a world in which truly free (i.e. copyleft-abiding) software is the norm, because it is very hard to imagine a non-capitalist world. My guess is that we would have very different technology arising from completely different incentive structures; probably far less advanced/sophisticated in some respects, but indeed more respectful of our freedom to know (but who's really going to use it?).