I'm missing something here, why not just cut some settings and lock 60fps? If developers implemented vsync correctly, the input lag may be minimal.
I thought this is mostly useful for enthusiasts who want really high settings at 1440p but can't consistently hit 60 on those.
Considering that G-Sync is almost exclusively available only on displays supporting high refresh rates, yeah, the actual benefits may well be circumstantial depending upon use. Think about it, if one owns a monitor that can display a high refresh rate, regardless of whether it supports G-Sync, why
wouldn't one then want to prioritize adjusting game settings as needed to achieve a framerate that properly takes advantage of whats arguably the most important feature of the display, the high refresh rate?
Now, if one does have a high, stable framerate to go along with a high refresh rate, what's the benefit of G-Sync, relative to V-sync being off? Honestly, if one were to claim that they can actually see any appreciable screen tearing in properly developed games that are consistently rendering at frames per second anywhere north of 100, I wouldn't believe them. That's like claiming to be able to see the difference between 120 fps and 144 fps - it doubtlessly exists, but on a practical level normal people just don't have the acuity to see it. Similarly, screen tearing becomes less noticeable at high framerates, the severity of any tearing, whether lateral or vertical (and your ability to see it as a result), decreases significantly as frametime does.
In a situation where one has a stable, high framerate there's no terrible downside to just playing with v-sync off - there's no additional input lag nor appreciable tearing. Alternatively, one can pay a ~$200 premium for G-Sync (and ULMB, of equally finicky benefit to gaming) and then be forced to accept having only a DP input as a tradeoff. Even in the case of 1440p resolution displays, for which G-Sync becomes much more practically beneficial, again, considering that
all G-Sync enabled monitors have high refresh rates, it would be better suiting the most important capabilities of the monitor in any situation in which fully ideal hardware is absent to just lower the rendering resolution and any other settings to maintain the high framerate.
I'd like to think most PC gamers, given the choice of picking either smoother gameplay or better looking gameplay, would chose the former in most situations, and if that's the case for you then G-Sync is of a limited benefit. Perhaps part of the misconception some folks seem to have about G-Sync lies in the presupposition that it's solving a problem to begin with, when that's not necessarily true in all cases - one of those being a case that happens to be applicable to each and every current owner of a G-Sync display.