Arm64 (M3) lags behind in some single core benchmarks vs Intel's high end desktop CPUs and is abysmal in multi-core benchmarks due to the limited number of cores, at least according to https://www.cpu-monkey.com.

Granted, the Intel CPU at the high end is pulling 250W+ (or was it 300W+?).

There are places for both architectures. I don't see x86 going anywhere unless Intel folds and ceases to design chips. Not sure AMD could power on alone given their current market share, though I certainly hope they could as a user of their chips in the desktop (and conversely, an M2 Air for my laptop).