This has sort of been understood for a while, though? It’s down to what you design it for. ARM chips have historically been designed to be small and low power whereas x86 has focused more on high performance. So obviously x86 is playing catch up on power management (for lower power states) but can have good efficiency at higher power. The front-end (the part that decodes instructions) is just a small piece of what makes a modern processor good, and is just about the only thing that is necessarily different between x86 and ARM (and RISC-V too).
This has sort of been understood for a while, though? It’s down to what you design it for. ARM chips have historically been designed to be small and low power whereas x86 has focused more on high performance. So obviously x86 is playing catch up on power management (for lower power states) but can have good efficiency at higher power. The front-end (the part that decodes instructions) is just a small piece of what makes a modern processor good, and is just about the only thing that is necessarily different between x86 and ARM (and RISC-V too).