x86 isn't dead, in the same way the ARM wasn't dead when the Raspberry Pi existed. Until we see 5nm x86 chips, it's going to be awfully hard to evaluate just how large of a lead ARM has on the desktop. And that's before we get to the real sticking points; legacy software. x86 is really, really good at maintaining backwards compatibility, and even has a number of objective leads over ARM in it's current iteration (for example, native SIMD beats the pants off NEON any day of the week). For ARM to claim supremacy, it's going to need to run the same software that x86 does, without overhead. Simply due to the difference in architecture, that's going to be astronomically difficult.<p>A more likely theory is that we've now entered the big.LITTLE era. Intel has already begun to pivot their desktop line to the big.LITTLE design, and while AMD's next line won't follow suit, they've discussed bringing the architecture to the CPUs after that. x86 has still got quite a bit of gas left in the tank, and now that RISC-V is getting taped out, a lot of people are starting to realize that a more modular approach to RISC CPUs is probably smarter than how ARM exists in it's current iterations. Plus, ARM is still proprietary (arguably moreso than x86), whereas RISC-V is fully open for anyone to use and manufacture. Simply from a technical side, I think RISC-V is going to eat ARM's lunch within the decade, and I also think traditional architectures like x86 aren't going away any time soon. Time will tell.