Although I'm supportive of your cause I find it ultimately futile. Developing and maintaining a mobile operating system is a hugely expensive endeavor. Only a wildly profitable company like Google could do so and give it away for free.
Linux simply isn't up to the task despite there being some touch-enabled user interfaces available for it. There's so much more people expect from their mobile these days.
The best option would be to use /e/OS or GrapheneOS to limit your exposure to Google's incessant spying and tracking.
Maybe you should write a blog about it. I'm interested.
I'm afraid there will be too many corners cut. The most important being the lack of available software. I'm of the notion that a computer without software is nothing more than a box of wires.
Linux simply isn't up to the task despite there being some touch-enabled user interfaces available for it. There's so much more people expect from their mobile these days.
The best option would be to use /e/OS or GrapheneOS to limit your exposure to Google's incessant spying and tracking.