Of course the technically correct answer I'm not looking for is "because Apple optimized it better" :D, I'm looking more at the (obviously probably extrpolated/guessed) path they took to get there. For example perhaps the increased memory bandwidth contributed (ie $pc go brrrrt :P) but like... this is like the elephant in the room that Apple is basically The Best™ ARM shop in town right now, and I guess I'm trying to reason both about the engineering (how Apple got to where they are now) and the market reaction (how Apple and everyone else are going to go forward).
[1]: https://www.anandtech.com/show/16226/apple-silicon-m1-a14-de...
[2]: https://www.anandtech.com/show/16192/the-iphone-12-review/2
At a higher level it is just hard to do designs at this complexity so the dominating factor is budget divided by how many different products the team needs to make. Intel is the outlier, they managed to sabotage their own dominant position, but across the rest of the CPU world this holds true.