I love the idea of RTR, almost as much as I realize it's impracticality and limited applicability.
For example, take iPhones. I would love to have a modular, user-replaceable (or serviceable) battery. But for that to be a reality, the entire phone would need to be redesigned, enlarged, and increase in price. Personally, I would pay more for a replaceable battery in my family's iPhones, but how many others would? Should Apple be required to accommodate my preferences? Someone else's contradictory preferences?
The argument for RTR is stronger with larger-ticket (5+ figure) items. But not entirely bulletproof either.
I like working on my cars, upto and including suspension, tranny, and engine swaps/rebuilds. But would I ever dare touch a 350V or 800V battery drivetrain on an EV (without fully discharging it, somehow) - hell NO!. If an EV value drops to <$20K in 8 years (when battery warranty runs out), and replacement battery costs more than the residual value of the car, would I replace it? Hell No. Then what's the point of insisting on RTR?
Still, I do want to have access to service manuals with all torque values for all the nuts and bolts on all my cars. A full repair manual would be even better, but the demand for those has been declining for decades. I can't even get one for my current ICE cars, never mind the EVs:
http://www.bentleypublishers.com/
*sigh*