The EU is introducing legal laws that will combat planned obsolescence. And that protect the right to repair. The EU is also fed up with manufactures thinking they can get away with everything. Those laws will also have a effect across the world because its easier to design on product that applies to the strictest laws, then two products.

So yea, Apple their gravy train is going to run into a massive road block. In the US states are also starting to rectify laws that push the right to repair.

Its one of the reasons why Apple "suddenly" allows repair shops to buy parts. As a way to change the narrative. Of course that buying parts has "issues" Apple style. A grifter is going to grift.

People that buy MacBooks don’t care, or at least they don’t care enough to buy something else.

As to your second point, MacBooks have been available for how long now? And yet thinkpads still exist.

When I have parts in my MacBook Air die, I guess I'll find out. It's 10 years old now and doesn't show any sign of breakage. I'm pretty sure it's paid itself off several times over.

Since the new Air lacks even a fan, it seems even less likely to need service.