On raw performance might, the M4 really does live up to Apple’s promises, should deliver. Single core is up about 20% compared to all M3 chips and more than 40% compared to M2. The generational computational leap from the previous M2 iPad Pro is at least a 42% jump on single-core and multi-core.
The performances is not inherent to ARM, x86 can definitely catch up to this.
In theory yes if they can handle thermals, but I don’t see that happening.