The Mac hardware does limit the choice of distributions a bit. Besides that I can highly recommend Debian 12 as a rock solid base system with Nix as package manager to get latest and greatest software. Actually the nice thing is that you can use Nix package manager on any Linux distribution.
Actually there’s an idea sparking up on me.
When I was a junior programmer there were some business guys coming up with the requirement to implement their own validation language (similar to regex). I always thought it is totally stupid to invent your own instead of using something that already exists. But it turned out to be great fun implementing it. I had no prior knowledge in implementing parsers and interpreters. But man I was so proud after I came up with my own solution for the problem. It was such fun, that I even was doing over hours. At the end I create my own tokenizer, a parser and an interpreter. Even something similar to what I now know most people would call an AST (abstract syntax tree).
However, I know I have bought the Crafting Interpreters book without having read it. I really should start digging into it.
Yea doing some FOSS contributions definitely was something I always was considering. But then as soon as I was looking for the right project things started to get complicated again. And even if you find a cool project you look into the issue list and imposter-syndrome starts kicking in.
Properly just Process Manager with the icon from macOS Activity Monitor.
Kagi. Very happy with it. Best $5 it recently invested. Gives me much better results than Google and all the others.
I am not an Arch-user, but I would say so. At least Nix itself claims that their unstable channel is the largest and most up-to-date package repository currently followed by AUR. So yes, I think you can have best of both worlds - a rock solid base system with the newest software via Nix. It even gets better with Home Manager.