Your graphics card might be cheaper than a whole console, but you still spent more money on a computer initially, so you would have to compare the cost of two consoles to one new computer and an upgrade.
And it likely is better performance now on PC versus console now for only a bit more money, but PC’s haven’t caught up on price for equivalent performance and likely never will.
And I say this as someone whose last console that was bought for its performance was a PS3.