Obviously that was built upon years of iPhone experience, but it shows they can lag behind, buy from other vendors, and still win when it becomes worth it to them.
They could change the architecture again tonight, and start releasing new machines with it. The users will adopt because there is literally no other choice.
Every machine they release will be fastest and most capable on the platform, because there is no other option
You can also voluntarily cut off huge chunks of your own app ecosystem intentionally, by giving up 32bit support and requiring everything to be 64bit capable.
...because users have no other choice when only one vendor controls the both the hardware+software. They can either use the apps still available to them, or they can leave. And the cost of leaving for users is a lot higher.
Microsoft and Qualcomm already knew the performance of x86 app emulation on windows was killing the ARM machine lineup, so Qualcomm was working on extensions to their chips and Microsoft on having Windows support them already, but ARM64EC and Prism didn't launch for two years after the M1 shipped.
I had the initial m1 air, and it was remarkable how useable it was. You'd expect all sorts of friction and issue but mostly things just worked (very fast). Even with some Rosetta overhead it was still fast compared to intel macs.
They do the things they think they can do very well.
Why would they try to build electric batteries, wireless modems, electric cars, solar cells, or quantum computers, if their R&D hadn't already determined that they would likely be able to do so Very Well?
It's not like any of those are really in their primary lines of business anyway.
They (Apple) bought out intel's wireless modems and are using them instead of Qualcomm's chips. IIRC, they aren't the best in class when it comes to raw throughput, but quite good in terms of throughput vs power consumption.
They do not make their own screens because they can source screens from multiple sources and work with those manufacturers to create screens with the properties they want. Same thing with them relying on others for electric batteries - there are plenty of manufacturers to provide batteries to Apple's spec.
They created their own wireless modems because there's only one company they were able to purchase modems from, and those modems did not necessarily have the features Apple wanted.
Apple hasn't announced any interest in selling electric cars, solar cell technology, or quantum computing platforms. I wouldn't expect them to do so until they had a consumer product ready for sale. I doubt they are planning to come out with products in any of these categories soon.
But this approach may not work in other areas: e.g. building electric batteries, wireless modems, electric cars, solar cell technology, quantum computing etc.
Essentially Apple got lucky with AI but it needs to keep investing in cutting edge technology in the various broad areas it operates in and not let others get too far ahead !