I watched one of Louis' videos[0] yesterday where he doesn't think Apple's ARM transition won't make things harder. He mentions that CPU failure is rare, and replacement CPUs aren't easy to get today, because they are salvaged from other machines, and can't be ordered from places like Newegg or Amazon. Almost all of his repairs involve components that aren't the CPU.

[0] https://youtu.be/T_2LnFAGypM?t=175