That's a completely reasonable challenge, and I might be wrong. My very amateur speculation is that, in the mobile space, Apple got incrementally better over time. Rank-and-file Android users didn't really notice the performance gap and thus didn't demand faster chips. M1 changed expectations for the laptop market virtually overnight, and rank-and-file users will expect M1 performance, battery life, etc. I think this represents an enormous market opportunity for PC manufacturers and thus chip suppliers that didn't really exist circa A9.

My key assumption is that there's some pareto principle at play--80% of the M1's performance gains over the next best generic ARM chip are due to a handful of key innovations while the remaining 20% come from a long tail of incremental improvements. This would mean that generic manufacturers could copy those handful of key innovations (modulo IP rights, which might be another fatal flaw in my speculation) and recoup 80% of that performance gap in just a few years. If that assumption is bad and the performance is entirely an accumulation of lots of minor innovations over time, then I suspect it will take chip manufacturers quite a lot longer to catch up.

There's more to it than chip design though. There is the OS work to take advantage of the chip's new features. And designing new chip features to accommodate sw bottlenecks. Apple has very close collaboration between software and hardware engineering, while in the competitive space, those two things are not under the same roof. Makes it tougher.

True, and I don’t expect generic manufacturers to completely close the gap between them and Apple, but I do expect there will be enough to copy that we’ll still see a step change in PC performance.