I think Apple being as big, and making the big technological leap with M1 convinced a lot of customers to buy the new Macs. Even those that technically weren’t needing one/upgrade. Now, that curiosity bubble has saturated with the M2 being an iterative improvement and the customer base certainly not as desperate (intel to M1). Given enough time, I think the Macs will continue to gain market share. Most tech companies…
Companies usually buy base models. Apple is also struggling with supply chain, as M1 is still prominent. Another feature of this issue is that because of their parsimonious storage configuration and linkage of M2 chip and storage, upgrades are nuts - it costs as much as an iPhone to get a storage upgrade that is like $100 with commodity SSD storage.
I generally agree that Apple's SSD and RAM upgrades are too expensive. I'd like them to be cheaper.
However, I'd like to point out that Apple's SSDs have built-in protection against data-loss from power loss which is usually an enterprise SSD feature. Also, Apple uses LPDDR5 on their Macs which are quite a bit more expensive than DDR4/DDR5. In addition, there's some evidence that Apple's LPDDR5 is actually not off the shelf and is specialized specifically for Apple.[0]
That said, yea I think Apple is a bit stingy with SSD and RAM upgrades.
[0]https://forums.macrumors.com/threads/24gb-macbook-air-m2-ram...