While mouse and keyboard is awesome for many games, a few benefit from the layout of a gamepad (or the way it’s used). There was a drought in these for a few years, particularly around the ~2007 time-frame, but this console generation provides us PC gamers with quite a few competent options. When they launched, both the PS4 and the Xbox One allowed their controllers to be used on the PC, and both eventually provided wireless adapters to make it function. Microsoft did it for Windows 10, and Sony did it for PlayStation Now. Even Valve got their Steam Controller out there, which is definitely an alternate alternative, like it or hate it. Personally, I’ve never tried.
While Nintendo hasn’t really ever supported the PC market, apart from, like, Mario is Missing, their Bluetooth-based controllers also never really tried to block PCs from using them. Apparently, the Nintendo Switch is no exception, and its Pro Controller seemingly just connects with the old gamepad API.
This isn’t supported, so it’s probably best to not go out and buy it for the PC, but feel free to try it if you already have a Switch and Pro Controller (and a Bluetooth adapter for your PC).