I made the switch when windows ME was released, right now I’m using win10 for work because of some software that really doesn’t have an alternative in Linux but I do run it on all of my other computers. Benefits:

• customization: If you want a desktop environment there’s KDE, Gnome or XFCE, if you want just windows or a tiling window manager there’s tons of them too
• package managers: update all your software on your own terms while you brew some coffee.
• scripting capabilities: you can automate lots of stuff with bash.
• scalability: do you have a potato computer, no problem, do you have a nice one, even better.

Edit: I forgot to say that I run Debian on most of my machines.

¿What did I miss?