- When the first MacBook Air was released, for a long time no other vendor came close to producing anything in that form factor with that build quality and reasonable performance (much better with gen2 though).
- When the MacBook Pro retina was released, there was no other laptop on the market with a screen like that for quite a while.
- MagSafe was a brilliant invention that, together with massively better battery life, gave them a real edge in this market way before all that.
These are just a few examples. I didn't even mention the trackpad yet. Up until the 2015 model, the MacBook Pro was pretty much the gold standard when it comes to a well-balanced package for the mobile professional. Surely some have very specific needs that require a real workstation, but you make it sound like Apple did not play any meaningful role at all, which I think is unfair.
The point is that other vendors caught up while Apple regressed in most areas except for pricing. Their premium used to be justified, but not quite anymore.