Much cheaper, much smaller, much easier to set up and use and trust it'll all just work.

If you've already got a basic laptop you use for everything else, and are just looking for a normal gaming experience (not modding or cheating or maxing out graphics), why would you buy a PC instead? It's all downsides.

(If you don't have a laptop and already do all your computing on a PC desktop then using that for gaming makes more sense. But even then, your desktop is often in your home office while you want to do your gaming on your big-screen TV -- so you still get a console.)