Is it for folks who are focused on going below the application layer (working on OS/Kernal etc) or just general. I find my MacOS to be such a comfortable system to hack and wonder if I actually need to move to Linux natively to get more involved in projects below the application layer.
I've enjoyed learning hacking skills by configuring GNU/Linux partially guided by an excellent MIT course by MacOS users (freely available at https://missing.csail.mit.edu/). On MacOS you can get a lot out of customizing your shell, text editor, terminal multiplexer, etc. with dotfiles. But I prefer a more completely free (libre/open) operating system because it doesn't stop there, I've patched and compiled my own custom window manager as well, and my entire operating system has the level of hackability that I love in the terminal. I guess all of the software I've mentioned is not below the application layer but above other applications (except for the most part the text editor).