My experience is the same as yours. When I rode the same regular routes on my gravel bike on slick 38s vs my road bike on slick 25s (up from 23s, as big as I c

My experience is the same as yours. When I rode the same regular routes on my gravel bike on slick 38s vs my road bike on slick 25s (up from 23s, as big as I could fit!), the road bike felt faster but GPS data didn't really back it up over the course of a whole ride. The road bike is a bit more nimble with twitchier handling sure, but the more jarring ride of the skinny tires gives the illusion of speed. But in the real, non-racing world the data tells a different story. At the limit I have no doubt the road bike is ultimately faster, but that's not most of my riding. I'm not a racer but am an avid and reasonably fit recreational rider, so I ditched the road bike entirely and enjoy my more comfortable and practical gravel bike, with minimal speed penalty. Plus I can ride on dirt roads and broken pavement with ease and comfort, to boot. I think most riders are better served by gravel/endurance bikes than pure road bikes.