At a certain point you have no more benefits from end user variety. Think about it this way - what benefits would you get if each house had a different standar

At a certain point you have no more benefits from end user variety. Think about it this way - what benefits would you get if each house had a different standard of electricity delivery? Let's say you have DC 300V, your neighbor AC 220V 50hz... meanwhile the building across the street was all three phase AC 150V 100hz. You wouldn't be able to buy a random TV and be sure that it works. In the end either ARM or RISC-V will displace Intel x86. And you'll have much more progress, just like the progress in ARM space was much more rapid than x86 space.