I haven't used Dagger but it looks like a fundamentally different design from traditional CI engines, so some people might have issues moving to it.

I recommend Drone.io or WoodpeckerCI for hosting your own CI. It's a very good design; very simple, easy to run, easy to use, integrates with most systems you'd want to, abstracts away components rather than tightly integrating them, and you don't need to be a programmer to use it. So basically the opposite of Dagger.