Well SSD are kind of the most important parts. And I’d say 99.9999% have upgradable RAM and storage
It's more serious than that though, IMO. For instance, if your 4 year old MacBook or MacBook Pro fails, such as via a water spill on the keyboard, in Australia at least, Apple will charge a fortune to fix it. If you take that Apple computer to a PC repair place in Australia, they will fix it for a lot less money. But if it was an X86 PC notebook, it would be fixed very cheaply.
That frustrates owners, especially youth, who probably got an Apple at School or University (college), and who are aware that many compatriots point out Apple's weaknesses in various areas. Apple should be repairing their hardware cheaper than anyone else can. In Australia, they rip you off, IMO. If you complain, then, if your lucky, they'll fix it cheaply. But the hassle here with Apple is a poisonous experience, and quite contrary to dealing with PCs and PC notebooks where the service shops compete and hence provide value and they try to establish a personal relationship.
Apple are designing their hardware - for example with I think the new iPhone 13 - so that if a 3rd party opens an iPhone 13, it becomes a brick. So I'm told ... please excuse me if I am wrong about that.
The "value" criteria is something that I think youth and up to mid 30 year olds, who have had a tech issue, or have a performance desire - hold dear. Apple's business model for service in Australia, makes Apple appear unfriendly IMO, unsympathetic and greedy. The Genius's don't seem that smart, except in making high profits from a misfortune that would be cheap to repair on a PC. That damages Apple's image with people here on this thread, who love their gaming notebooks, and I suspect, they have a strong emotional connection with their clunky but awesome in some ways hybrid "gaming notebook" computers.
Strategically, it does seem to me though, that the X-Box was a tool to offer economy of scale to game businesses, via Windows and MS's console. And Apple have never seemed to want to get into the console arena.
As said several have said here, and I think it makes strategic sense, the opening door for games on an Apple Pro notebook, will be games written for iPads. I do wonder if an iPad with an M Pro in it, could be a fun games machine. Its not impossible to also wonder about VR ... surely VR makes a better game experience, and with VR, who needs a powerful GPU?