I remember in 2007, buying my first MacBook. It came with an enormous 2gb of RAM. I asked about upgrading it. The guy leaned in conspiratorially and told me that Apple’s RAM upgrades were a rip-off, and that I’d be better of buying it elsewhere. So I did, for half of what Apple were asking.
This is a grift that Apple have had for far too long, and there’s a part of me that’s convinced that their move to soldered RAM was to stop people upgrading after the fact more than it was about SOC efficiencies.
Probably not as far off as youd think. A lot of the efficiency comes from the smaller node that apple uses. If both amd and apple silicon processors are being compared and that are using the same node, then they are pretty equivalent. 6900hx is still tsmc 7 nm (later version) while the new m4 is on 3 nm. Both are still pretty efficient. It’s not like tiger lake levels of inefficient.