Gravel bikes are general purpose bikes that are better for a lot of people's use case than more traditional go-fast bikes. I was on a very long group road ride riding my gravel bike (with 40mm slick tires) and dropped my phone. Someone on a tandem saw it happen and attacked the group instead of slow rolling for a few minutes like a normal person. Not sure what the point of that was, but I caught up to the group after about 5 miles and pulled hard enough that they got dropped from the group. Maybe if I had a aero road bike, it would have been a little less effort.