Apple specifically designed their ARM CPUs to be able to efficiently translate x86 code. A generic ARM CPU won’t be able to get the same performance. Maybe other manufacturers will do the same as ARM PCs get more common.

The fact that almost no PC games support ARM is stopping them. When lots game developers start releasing ARM or RISC-V versions, then Valve may consider an ARM or RISC-V Steam Deck. They will still have to have an emulator to run the older x86 games though.