I had the three bikes you spoke of but in the end they never got utalized as much as I thought, so this year I sold my gravel bike and trainer/project (aero) bike and bought a lightweight climbing bike that I use as an all-road bike w/ 30c tubeless tires to go along with my aero bike. Even then I rarely ride gravel, so I have been using my lightweight bike for rides that I know will have a ton of climbing, for events, and for training in the winter. I still use my aero bike 70% of the time since most of my riding has sub 1000 ft elevation.

point being, while having various bikes is nice you have to do a lot of gravel or gravel that is beyond just pact dirt trails to warrant a dedicated gravel bike and IMO the current gen of aero bikes have gotten so light with such wide tire clearance that having even a climbing bike or an all road bike is somewhat redundant. I am tempted at this point to sell my two bikes and even just go with a Tarmac SL8 and use a mid depth wheelset w/ some 30c-32c tubeless tires