So far, but how far... you should ask yourself. Businesses make decision in light of the current reality. So far Microsoft has had to deal with devs using open source stack on Mac due to things like Homebrew, forcing them to incorporate a whole Linux distro into their OS to keep devs there. So as long as you can keep open source going, you can hold the gates. But question is how long... indefinitely? As the market grows there is room but when the market shrinks and has maturity how much room will be left. And general network effects of the cloud are already felt all over the place, like a document produced on a pc hardly ever stays on the PC it ends up on Google Mail, Google Drive, Microsoft 365, etc. There is no privacy and basically at this point is a joke.

But there are strong network effects. The more people who use a platform, the more apps there are and vice versa.

Other people not caring about openness is like littering. Even if it helps you a little (you don't have to trade against any of the things Apple forces you to trade against), it's a huge problem when everybody does it.