That's a bit of a silly comparison, especially when you say it depends on what performance you are happy with. If you're happy with the performance of a PS4/Xbone then there's no need to spend £500 on a top end GFX card when a £200 one will do. If you "need" the performance of a 980Ti, then the point is moot since a PS4/Xbone wont be good enough.
There's no reason you can't lounge back and game on a large TV in the comfort of a sofa with a PC. It also has the added benefit that you have the
choice to sit at a desk if you want to play games which are more suited to M&KB such as shooters or RTS.
IMO:
PC
Pros:
Flexibility
Cheaper games
Backwards compatibility
Better performance/graphics*
Cheaper to upgrade**
Cons:
Higher up-front costs*
Slightly higher maintenance (e.g. drivers, updates etc [although this is becoming less of a difference since current gen consoles are constantly updating too])
Sometimes compatibility issues
* Very dependant on how much you spend
** Depends how often you upgrade and what you upgrade to
Console
Pros:
"it just works"
Can trade in games
Lower upfront costs
Cons:
No flexibility - it's a gaming machine (with some media functionality [good luck playing any unsupported formats though])
More expensive games
More expensive to upgrade
No backwards compatibility
Basically they both have advantages and disadvantages, it just depends which are the biggest factors for you.
What swung the PS4 vs new PC decision for me was the fact that getting a decent PC would mean a huge library of games I already own being available to play, whereas buying a PS4 would mean no games to play, I have my PC connected to my TV & 5.1 system for when I feel like sitting back and chilling for a "cinematic" experience, but I also have a desk set up with a 34" 21:9 screen for when I want to do some "proper" gaming (or the GF is watching I'm a celebrity jungle on the TV

)