It's weird to look at this in the context of Google and T-Mobile almost shipping the first Android devices with a $10 a month unlimited data only plan...
It sounds like you are conflating AArch64 with Apple. Apple had nothing to do with AArch64, it was developed by ARM in-house; Apple simply released the first AArch64-compatible core (outside of ARM's Cortex series).
Apple is able to do what they want because they have an architectural license; not a core license. It's the same reason Nvidia, Cavium, etc are able to design their own cores irrespective of the Cortex series. That's what an architectural license is for. While MediaTek, HiSilicon, etc are limited to using the Cortex SIP.
Then AppliedMicro had a hardware version to demo.
Apple simply had the first to market consumer product with one. Them buying up a good chunk of the fab space needed to produce them at the time probably contributed to that.
I don't think it's arguable that the M1 wasn't a game changer though. M1 firmly established Apple's design prowess at the laptop/desktop class chip game. It was no longer arguable that mere phone chips weren't comparable to desktop class CPUs. That claim is dead. It also enabled performance and power efficiency levels years ahead of the competition, giving tangible immediate benefits to customers.
So revolutionary? It's a matter of opinion, but I think it was a watershed moment and permanently changed the technical landscape for CPUs running 'full blown' desktop class software.