Bike recs to pull kids trailer and road/sprint tri capable

Hi! Looking for recommendations for a bike that is sturdy enough to pull a kids bike trailer, but also road capable for quicker rides without the kids.

Currently, I have a Specialize Sirrus 2.0 that I use just to pull the bike trailer, but it’s a very basic set up that doesn’t have a lot of help for pulling, especially hills. I also have an older, used Cannondale road bike that I used last year for a sprint tri.

I’m not familiar with bikes at all so I’m not really sure what I will need, but my hope is to consolidate the two bikes I use now to just one better quality bike. When I pull the kids, it’s typically on paved trails/sidewalks 10-15mi, but for myself, I enjoy longer, quicker road rides. Being able to use it for sprint tris would be ideal as well! I’ve been told that a gravel bike could work, but looking for personal experiences!