Declarative setup with NixOS. I can choose what services and software gets run and installed. I can define my user experience (sway, tiling wm). I have the control on OS updates, not Apple. Native docker. CLI works much better on Linux compared to Apple; macOS command line tools feel limited and crippled compared to almost any Linux distribution.

And, of course, I can modify any of the tools I use. The whole stack is open source.