FEX-emu, box86, and qemu-user allow x86 / x64 programs to run on ARM devices. Taki Udon got Crysis running on some no-name Chinese Android gizmos. Portal 2 is genuinely playable on a $40 handheld.
I expect the x86 ISA will remain central for at least another decade. I have no idea why anyone in the last decade has bought Intel. If it's not your money, and you absolutely required the most powerful cores for closed-source software, yeah okay I guess. But AMD's always been cheaper per oomph, ARM gizmos run at like one-tenth the power consumption, and RISC-V is gonna surprise the hell out of folks once it leaves the low-end market.
The userland CPU emulation thing is the only reason RISC-V will matter to normal people. It has no software. It does not meaningfully exist yet. Binary compatibility is 100% obstacle, 0% benefit. But the inevitable rush to make x86 programs run on ARM will obviously be tremendous progress toward making x86 programs run on... anything. Melt it all down to LLVM and all you need is a native back-end. Show off Dave The Diver on Amiga via that one Debian fork for 68040.
Melt it down to SPIR-V instead for translation from Vulkan to whatever, and we might find out how well Tears Of The Kingdom runs on $5 worth of hardware.