If you set it to medium you should get a smooth experience. You don't have to do anything I'd call "fiddling", and being optimized for a specific GPU is overrated (and not even true with the current consoles). Especially when you have a much better CPU.

> Of course if one pours 5x the amount of money into PC that would be spent on console, there needs to be some inner justification.

You can get a prettier and smoother experience if you do that and don't put the settings on super-ultra.

But also, if you're already going to have a computer, popping in a better-than-console GPU is cheaper than a console.