Popularity is increasingly necessary to be able to actually use the OS. Hardware is constantly evolving, you need to keep up with everything from the new CPU architectures to the boot environment to drivers. Software is constantly evolving (worsening) too, if you want to interact with the web you need to be able to run a modern browser. Without popularity, there will be neither volunteers nor coprorate donors to do all this monumental work.
If corporate involvement is a bigger issue for you than usability, GNU Guix/Hurd is always there for you. I have it set up on an old laptop, it is kinda fun in a way but not really usable for anything.