Faster, probably, but 2x+ Faster like in PowerPC > Intel very unlikely. Which is why there’s much less likely to be enough performance budget for effective emulation.
We've been asking why Apple doesn't already do it.
The same architecture can generally scale to 10x over a few process generations.
Possibly a patent issue also
Clock speeds alone can probably increase by 30%. Caches and internal datapaths can double or more. Then you can start to add in more execution units or more expensive branch-prediciton or even new more power-hungry instructions.
A 4 Watt Intel Pentium 4410Y Kaby Lake for mobile devices gets about 1800 on Geekbench, while a 115 Watt Intel Core i7-7700K Kaby Lake for desktops gets 5600.
I'm just going to say it: the Apple laptop CPU is going to get Geekbench score... above 9000!
And, yes, I do have a CPU design background.
Once you understand this, then you can understand how CPU designers work to predict future performance. CPU designers use artificial testbenches.
Or even further they could bake a "rosetta" into the chip's microcode and have their CPU natively support the x86 instruction set along with ARM or whatever they come up with.