I'd love to, but mobile phones are bad-compromise-all-the-way.

I can't live without a proper SSH client, and that requires a proper keyboard where you can actually do key combinations.

Any phone with a keyboard (and not ancient) can't receive an unofficial OS. e.g. blackberry Key2

Either because they do not have unlocked/vulnerable bootloaders, or because you must have the closed source driver running to be usable. Android is not opensource and even lineage OS still requires TONS of closed source binary blobs to even boot. There is zero open source android alternatives.