That helps (perhaps a lot, hard to say), but note that moving your design from 4 nm to 3 nm pitch isn’t as simple as recompiling your Verilog. So this is still a significant engineering achievement.
Apple is chasing a different design point from the desktop folks: low power and optimized more for single core workloads. Works for them but not of course for everyone.
The Mx machines aren’t SoCs in the sense a MediaTek part is: the main chip has a lot of integrated functional units, yes, but so do the Intel and AMD design. They do have multiple dice in a single package though.
Personally I don’t lose any sleep over the non-upgradability of RAM or mass storage. I started computing when you could add instructions by adding wires to the backplane, and later by writing your own microcode; you could build our own IO devices and wire them into the machine. Gradually we have had more and more integration, and RAM and mass storage are just the latest to go…and in exchange we get better performance and reliability.
I don’t hear people complaining that they can’t upgrade their disk drive’s write cache, or CPU’s cache for that matter. This is the way of the world.