My husband and I were wondering about this as well. I can never do Skarlet's F2>Blood tenticule on DS4 controller on PS4, but can do so with ease on PC (using the Xbox controller). I am not sure if it's a PS4 vs PC thing, or DS4 vs. Xbox controller thing that I can better do this.
Lag in general between consoles and PC is a pretty layered. Lag sources aggregate and this is just one, small lag source. If you aren't using the same display or even if you aren't using the same kind of display the same way, you could have a major lag source on one that isn't on the other.
Not sure about MK, but many FG's using the Unreal Engine have had additional latency on PS4. Sometimes efforts have been made to lower the problem, and other times not. Like Tekken used to have much higher input latency on PS4 than PC and it was something they worked to improve. I think it's still higher but it's better than it was. Upper SC6 players say SC6 on PS4 still has a gross amount of input latency compared to PC, and just don't want to go near that version of the game.
On PC people naturally tend to end up using monitors which trends towards lower display lag over TV's. TV's are much better than they were even a couple years ago, but you still have to be deliberate about what you buy to make sure you don't have several frames of delay added by your display device. So, it's possible for someone to end up with a lot less lag on PC just by accident and virtue of PS4 tending to suffer more as a platform than PC.
If someone was noticing a difference between platforms is also more likely that they are noticing those things, which are larger sources of lag, then an additional 7ms on a controller.
To make things even more muddled, even with PC being the better option lag wise, Steam can add latency if it's applying controller support for a game.
