The PC is for high end gaming. It's not cost effective (contrary to what you said I'm not sure it's ever been cost effective[1]) compared to consoles. It typically only gets close to consoles at the end of a console cycle because they have such a step-function and the pc has a far more granular cost/performance curve over time.

PC is really the only place where you get super high end framerates+resolution+graphics-fidelity combinations. It's only really cost effective if you upgrade slowly—a new cpu here, a new GPU there, amortizing the costs over the years. And the nvidia xx80/xx90 models are never the ones you'd buy if you are trying to be cost-effective. They are high end damn-the-money-just-give-me-all-the-graphics cards.

[1] maybe back in the era where the PS3 was $600, but even then a xbox 360 was cheaper and mostly just as good fidelity-wise.