By "vast majority" I mean that the standard repositories (which optionally includes extra repositories, like the Canonical Partner one) includes hundreds of thousands of programs, and GUIs are provided by the distro (e.g. the former Ubuntu Software Center).

I've checked several of the programs you've provided, and here's a report:

- Readarr: has docker image(s) in Docker Hub

- PhotoPrism: has docker image(s) in Docker Hub

- Prowlarr: has docker image(s) in Docker Hub

- Openbooks: has docker image(s) in Docker Hub

- Jackett: has native linux binary in the official Github releases

- FlareSolverr: has native linux binary in the official Github releases

- Transmission: it's commonly provided in the Linux distro repositories

Those who refuse to do such a minimal search and/or better look the Github releases page, they definitely deserve to stay on Windows, rather than spreading misinformation.

If a program doesn't to have a package for a given platform (no doubt about those cases), it's a developer's resources problem (and essentially, an O/S popularity one). It'd be ridiculous to say that having to manually install a certain program on Mac is inherent in Mac itself.