If you want, you can do anthing you want in Linux.

that sadly many cool foss apps don't have frontend GUI to be friendly with users

it doesn't secretly move all my files to OneDrive

command line interface 😀

It lets me do what ever I want without any silly workarounds.

gnome

It's all about freedom.

i guess the fact that is multi purpose, one can turn it into a desktop or in to a server.

doing everything in the #shell w/o the need of graphical interface (Xorg/wayland)

I like that it's under my control and I don't have to do tons of hidden registry hacks, settings tweaks and such to get a desktop that respects my privacy. (And not even that is guaranteed.)

I am in control of what is installed, what is running. There are multiple applications for most of my tasks and I can try them out and then use the one that works for me. My 'support calls' for my wife having problems has dropped to almost zero. Works well, very well with old hardware. An old laptop actually runs faster and is more stable then my modern corporate laptop.

It works good.

it's free also as in "free beer"

Freedom of choice.

I don't need to remember or write down a product key safely somewhere.

privacy

Freedom of choice (even if it comes with some responsibility).

not being slow AF as Windows

It is free(as in freedom), also, OS is called GNU and it is combined with Linux kernel. Also, I can use any DE with it.

Control.