Using Sailfish OS is just trading Android for another proprietary OS. Why even bother going to all that effort and still end up back in the same place?

We have real mobile linux distros like postmarket OS and actual open source desktop environments like Phosh or plasma/gnome mobile.

Hell yeah. Next, they can get a cut of every dollar made! Or a subscription service with strict usage limits and add-ons to re-enable disabled functionality. It’s one or the other.