I wanted to upgrade my M1 because it was going to swap a lot with only 8 gigs of RAM and because I wanted a machine that could run big LLMs locally. Ended up going 8G macbook air M1 -> 64G macbook pro M1. My other reasoning was that it would speed up compilation, which it has, but not by too much.

The M1 air is a very fast machine and is perfect for anyone doing normal things on the computer.