Linux

I honestly endorse the cult of thinkpads, get an old t-series or some other cheap model. They have excellent driver compatability and access to tinker with the hardware. If you want to build it out to be a behemoth with an i7-i9 with like 16gb and a small boot drive but a massive spinning rust drive that's doable. But it's also a good light machine, say you keep it on 8gb and a 256 or whatever stock is... that's still a good machine.

I'm currently running an ancient windows 7 era Dell machine and it works great its just showing it's age in physical condition and thermals. Unfortunately it is a tank of laptop when it comes to lugging it around (especially compared to a modern thin& light). but even that still has enough horsepower as a 2ng Gen core i3 with 8gb and a 1tb spinning rust drive, for some light stuff like ,music playing and writing.

You might think about tossing ubuntu with lxqt or sway on the MacBook. Just be sure you have a way to get internet set up most the wifi cards in MacBook don't work out of the box.