You’re unfortunately right that a Linux phone wouldn’t solve these problems and I’m with you that devs who bend the knee to Google have no interest in providing a Linux phone version - at least for the foreseeable future.
Once there’s a considerable market share for Linux phones (which may never be the case…), those users are potential customers and the tides will shift.
Until then it would at least provide a portable computer that can do a lot of the things current smartphones are capable of, but without the restrictions created by Google and Apple.

I have a more pessimistic view of bad scenarios.
Combine Google Play Integrity checks with being unable to install apps except they’re from the Play Store and you are at the whim of Google.
Right now I’m battling an app provider (of an app I rely on) who decided to start Play Integrity check shenanigans, although that’s in violation with their TOS. I know about not so great scenarios already. My alternative would be to cave and forfeit GrapheneOS, which I’m not willing to do.
We. need. Linuxphones!

I’m not saying I’m a fan of that, but at least Apple is upfront about the walled garden they offer and ever has been.
Google started differently, but turned around 180 degrees.

I don’t know, but in difference to Hacker’s Keyboard it still receives updates.
What’s for sure better (for my use case) is the broad range of layout customization.

I wasn’t aware of that.
Thanks for letting me know!

It took me years to find it and now that I did, I want to spread the word.
…I wasn’t looking non-stop for sure, but I can for sure say that I was running Android for years without that gem.

And that’s what gives (me) hope.
Were all as bleak as the rest, I’d hope for a hit by a meteor of the mass extinction event type.
…but there still is hope for change.

Google is paving the ground for Linuxphones.
It’s so blatantly obvious how evil they’ve become that it makes striving for alternatives a necessity.

It’s a totally different animal (and works best with some customization), but I can guarantee that it’s AI free: https://f-droid.org/packages/juloo.keyboard2