The radio stations i listen to have exactly 0 ads (rely on donations), unless you count as "ads" messages they haven't been paid to spread. Also worth noting, i personally don't consider ads as a freemium model, because the song is the same whether you bought the CD or listen to it on the radio. Whereas in the software world, the program is limited in the free version.

> tragedy of the commons

That is a largely exaggerated capitalist meme. I'm not saying it can't exist, but many areas of life throughout human history have been managed communally without any such tragedy so there's definitely ways around this problem.

> everyone does the bare minimum, because there's no reward for doing more

As someone living in free communes for a long time now, that's definitely not my experience. Yes, there will always be one or two people (and not necessarily always the same) doing little, but in my experience people can't stand doing nothing for so long. We all crave to be part of something and contribute to making life better for everyone... just try to play video-games non-stop and you'll see after a few months you'll want to do something else ;)

Also, in a free society, the reward for doing something, is the achievement of the task itself. In a capitalist society, tasks are rather meaningless: we do something useless, to get paid, to achieve some actual goals of ours. In a free society, we gather and decide on goals that make sense to us and how to reach them: there is less layers of indirection and a much tighter feedback loop which is much more rewarding than working for a boss.