The idea originated with Einstein in the middle of WWI, and it took until 1960 for the first working device to be made with lots of incremental progress in the middle. After that it's been a non-stop series of inventions each of which gave rise to new practical applications and new avenues of search. Originally described as 'a solution looking for a problem' it turned out that indeed, it was the solution to a lot of problems, we just didn't realize how applicable this tech would be.
Graphite with zero defects and perfect crystallinity has the same properties as graphene. It IS layers of graphene.
(This is all essentially true for carbon nanotubes, too, which are just tubes made of graphene… maybe graphene is more chemically reactive due to the ends of the sheets though.)
That's kinda how science goes. The first free-electron laser was built in 1971. It took decades to develop and commercialize free-electron lasers and we still in the early days.
It is rare for a single discovery to revolutionize everything especially in the 21st century. Typically it is a series of discoveries in a row that taken together allow new processes and technologies. Each discovery on that road is important.
The short term impacts of discoveries are overestimated, the long term impacts are underestimated.
On a 50-100 year time scale, the perception of graphene may be very different from what it is now. We are looking at a tadpole and saying, I thought these eggs were suppose to hatch into frogs, not tadpoles.