Free Software won because almost everyone, especially businesses can benefit from it. who is going to benefit from right to repair besides consumers and small repair shops?
Everyone as well? Lower costs, better looking carbon footprint, longer lifecycles, better secondhand market, more efficient software (if you don’t assume everyone uses a new phone, you design your apps/web apps with a little more care towards performance and battery efficiency), more competition between manufacturers (because it’s not a given that you’ll sell new devices every 2–3 years)…
Designing a very small device to be DIY repairable has a cost too.
Probably. I don’t think it’s much more than the cost of shrinking everything down and shaving 1/2 mm off your design or engineering a whole protocol, chips, and software to pair components together and implement “features” at the OS level to disable some things if it detects new parts.
You're right that customers don't care about Free software and yet it won. Free software has moved from a niche to dominating the software marketplace. The linux kernel, GNU coreutils, gcc, binutils - these are amazingly popular and keep getting ported to new platforms. And of course, Open Source software is yet more popular still.