There is a small yes, but not for that big of a gap. There is some minimal advantage, which is if the framerate goes above that of a screen(even at 30 fps caps, you might hit 31 occasionally depending on how it’s limited), you get screen tearing. Screen tearing is where new and old frame overlap causing the image to tear. VSYNC and other tech avoids this, but comes at a cost of a small delay in framerate.

So the solution is simply to cap framerate either to a divisible part of the framerate, eg. 30 fps for 60 Hz screens, 60 fps for 120 Hz. You want divisible because if you create 35 fps, the frames will not be done at the same time as the screen is with showing a frame. Thus the need to have it semi matched up.

But this is a rather big loss for a good screen, so you’d like to just cap fps to a few frames below the screen Hz. Modern technologies deal with that by talking better with the screen, so the screen shows a frame until given a next one. GSYNC and FreeSync are the ones that allow variable framerate without needing to match screen Hz and FPS. (There are some limitations, particularly they can be limited to some framerate ranges iirc, and if you go above screen refresh rate you’ll still have either screen tearing or VSYNC kick in with that extra delay.)

If your PC cannot keep a stable 60 fps due to performance issues it is better to lock it at 30.

For power saving. If you play unlocked then the engine generates more frames while consuming more power.