I'm willing to bet that the chance of someone having a PS4 is quite a bit higher than the chance of that same someone having a PC with a >=970 GPU though.
I don't know all of the hardware that is >= 970, but adding together the 970, 980, 780 Ti, and R9 200 series I get about 7.17% of users represented on the steam hardware and software survey. There's probably more cards on that list that are at or above a 970, but I don't know all of them.
Assuming that that survey is representative of the userbase, and we apply it to the latest active user estimate I've seen (via SteamSpy), which is about 140m, we get about 10m users that may have video cards at or above the 970 level.
I'm pretty sure that over double that amount of PS4s have been sold, so you're probably right.
Also I'm probably making a lot of people shake their heads in disbelief at my mathematical/statistical shenanigans here, but it's my first time trying to extrapolate stuff like this.