Yep, and i'm sure tons of GPUs can push every game maxed out to 150 fps @1440p right? Wait, that turns out to not be the case at all. G-sync would be beneficial because anyone thinking that any single GPU will push every game to the 144hz barrier @ 1440p would be VERY VERY wrong. G-sync would essentially go a long way to solve this problem by making gaming smooth at lower framerates where applicable. Make no mistake, at 1440p and high/ultra settings it is not a cakewalk. The games can be demanding if you're someone who links to crank settings. And you simply will never be able to hit 144+ fps in most AAA games consistently.
The big issue with G-sync right now is that the only thing available is the FPGA DIY kit, which is too expensive. Most buyers won't buy the DIY kit for that very reason (myself included), but the newer monitors will be using ASIC scalers with integrated g-sync which will be far cheaper; remember FPGA is expensive by nature but NV used it to speed the DIY kit to market. ASIC integration is far, far more cost effective and I do believe the integrated g-sync monitors will be reasonable in price. We'll see, though. I think the ROG swift is due for release in July - being that it's the first 144hz certified 1440p panel, i'm quite interested in it.