1.
The human eye is not limited to arbitrary numbers like "72 FPS". The way we see things is perceived dynamically and differently from each other, and our eyes compensate in different ways depending on what we are seeing.
LINK
2. Just because the display can't refresh faster than 60Hz doesn't mean that there won't be less lag. The reason we see lag is because of INPUT lag, not because of refresh lag.
EXAMPLE
In this test, for demonstration purposes, a finger is moving across a single axis at a rate of 1 unit/millisecond. The lag, therefore, would be 1 unit offset per millisecond of lag, per output update. This is observable in figure A. Using a 50ms lag display, there is a
50 unit offset on what is happening and what is actually displayed. On a 1ms lag display, there is a
1 unit offset on what is happening and what is displayed.
--snip--
Figure A: I destroy your argument with math.
As you can see, this technique of removing input lag
is mostly unaffected by display refresh rate. The output has dramatically improved when using even the same display! The results of output would be much smoother with a greater refresh rate, of course, but it does not have to be increased to see the fruits of this technological advance.
Q.E.D.