After riding a double for a few years, I am likely going back to a triple on my road/gravel bike for the very reason you mention: the middle ring.
On my triple I could just leave it in the middle ring for almost all flat and rolling terrain. With my double I am having to constantly shift the front rings and spend a lot of time in big/big which is not ideal, IMO.
There has been no discernible benefit for me using 2x on a road or gravel over the past few years.
MTB is different. I saw a lot of advantage going from 3x to 2x (even when it was just replacing a big ring with a bash guard).