A small number of very vocal users are really mad about what Firefox is doing with alternative revenue models. The same group loves Firefox Focus/Klar.
Why not build a new product called Firefox Focus for desktop with only about:config flags similarly how DevEdition is based on Beta? This Desktop Focus can have telemetry disabled, Pocket disabled, 3rd party isolation on, DNT on and any other privacy features people would want. It can even have private mode by default.
I personally hate it when people say that Brave, Waterfox, PaleMoon, Basilisk or even worst Opera and Vivaldi are more privacy-centric than Firefox. This would allow Mozilla to retain the corwn of the builders of the most privacy-friendly browser but still experiment with alternative revenue models.
I hope somebody at Mozilla is listening to this