Simplicity, no transmission. As to unsprung weight, designs like these have a ridiculous power density, so add only very little. Advanced suspensions are active anyway, so just part of the wheel robot.

I call it “installing software”.

There are tablets with docks available. E.g. I could use Pixel tablet with the hub for that, even with privacy-supporting GrapheneOS.

OpenBoot at Sun and Apple had a good thing going for a while. Too bad they didn’t release it as open source. In theory you could deliver architecture-independent drivers that ship as firmware on device.

Alternative ROM market is fringe de la fringe, so there’s sufficient used hardware available. I bought my 7a for 320 eur new and my tablet for 400 eur new though, so the Google tax (or, GOS tax, rather) was moderate.

Buy used. The other phone vendors haven’t been offering the security hardware GOS needs, so far. It might change soon enough though.

Don’t wait. GOS just works.