Thinking about the problems you will have with something you buy is naive? Considering a wide variety of parts on a laptop are proprietary I think serviceability and turn around time are big considerations.

I share the same concerns - due to the small form factor of these laptops, it isn't a standard, commodity you can find easily.

Especially in the Pixel's case where it is a limited production run to begin with.

It's not. It's actually a really good reason to buy electronics. Apple supports their devices very well.