I hear you, I think software is different because it has very few physical constraints.
My appetite for food is not infinite, I can only eat so much. Same, but less so, for cars, clothes, etc. in some abstract sense, maybe, there are people that want 100 cars, but not really.
Even with housing, demand is not really infinite. I don’t want to redo my kitchen every year.
But software, every company has a backlog far longer than they will ever be able to do, and the ROI is there for the most part.
This most certainly is not true. There are plenty of free things that don’t result in 100% consumption. Demand is based on peoples needs and preferences, not on how much is out there already. Think about libraries as an example.
Oxygen is definitely still monetized. Think about the canisters or the tanks that people use to go into high altitude environments. Hell, even in Denver or Aspen or Telluride you can go to an 'oxygen bar' for absurd prices. Hospitals will put you on oxygen and then bill you thousands for the service.
Beyond that, I have no doubt that there are some people who would willingly charge everyone for oxygen, if there was only a way. This would be driven by the idea that even though there is plenty in the atmosphere, a person only needs to be deprived of it for a little while before the situation becomes dire.