I could see myself paying let's say $100 a year for a polished Linux desktop. "Polished" meaning no screen tearing, video hw acceleration, working power management, macOS (or at least Windows) level of GUI consistency, nice package manager with a curated app store.
How many customers would be required to support a project like this?
Subscription models are customer kryptonite. They run screaming with pain when you propose them, and only grudgingly accept them when no other option exists.
Providing a subscription model for a desktop environment adds additional complexity. Do you want to be cut off from using your desktop when your subscription lapses? As a developer, I am not interested in you paying me $100 for a year and then be able to use the product for life. My mind will change if you are willing to pay $1000 up front.
As a software developer and entrepreneur, I founded companies that could sell software for $499, provide one upgrade and then charge a smaller amount for additional upgrades. Those days are over.
I recently spent a significant sum develop a mobile application for a niche market. It was well liked, worked well, provided a real solution for a real problem. It was offered as a subscription. Endless one star reviews and hate. It was offered for $49.99. Endless one star reviews and hate.
Something has gone wrong with consumer expectations on pricing and the effort required to fund development of software that meets customer expectations. I feel we are in a software dystopia and can't figure out how to fund product development.