My fear is that car manufacturers will turn cars into a totally dealer serviceable only thing (even more than they are now), like the car version of the glued shut Microsoft surface that gets a 1/10 on the ifixit repairability score.

In the case of Cruise this wouldn't be a problem because you wouldn't own the vehicle. Its a robotaxi service. Your point is still valid, though I'd ask, how do you even solve certain classes of issues? Like lets say you had to replace a camera. You can't just plop one in and have it work. There is a ton of complex calibration work that needs to happen, both intrinsic & extrinsic.

Service intervals based on time and usage combined with certified repair. From a passengers perspective airlines are strictly liable but presumably airlines could then sue the relevant third parties in such a case. I suspect a similar model could work fine for self driving cars.

Put a rfid tag in the tire, store how many rotations that tire takes over time. Once it reaches a threshold, refuse to spin that tire further.

Tire wear is a complex interaction of various factors such as compound, slippage, road surfaces, torque, weather etc and not just wheel revolutions