If you are using Gnome distros: you can feel exactly what it feels like getting back to working in a restricted, overhyped, overbranded environment like Windows.
If you are using Ubuntu: you can get advertising during your system’s software upgrades. No, really.
If you are using Arch: you can post aroudn the internet saying you use Arch btw.
Depending on the distro, you can use some alternative software stacks, but that’s mostly the backend (eg.: systemd versus openRC, Apache vs Nginx, X vs Wayland); most “desktop app” level is mostly the same for each desktop environment, is kinda the point.