Apple grew exponentially because of iPhone and changed not only their future, but that of effectively all of us who use our smart phones in a way that no other company could have foreseen. They’ve been stuck in the laptop and desktop market because of their reliance on Intel, much like every other PC maker. They could only do so much with the complete crap scheduling and advancements that Intel offered.
And the days of building your own devices, upgrading, etc. - they’re done, gone. Other than a tiny niche group of tech nerds, the mass volumes of people and companies don’t want to buy a device that they have to think about upgrading parts and pieces. Frankly, what you’re going to see is that most other PC makers are going to move away from selling beige boxes and upgradable laptops, just as Apple has, because they’re not making money by selling products that they only get one sale out of.
The same thing with gaming computers. It’s a niche market and as developers of games realize the power of Apple Silicon, they too will start shifting from the PC market.