The fact that the models are getting more complex may itself be a sign that we’re framing things poorly. For example, when we had a geocentric model of the solar system. It wasn’t inherently wrong. The problem was that using the earth as the focal point made it very difficult to express the orbits of other planets, and people had to integrate ideas like retrograde motion and so on. Then we started using the heliocentric model and all these problems went away.

Likewise, it’s entirely possible that we’ll come up with a a new model that makes it far easier to express all the different phenomena we’re observing. Obviously there’s no guarantee of that, but that’s one possibility to consider.

You’re right that the rate of discovery of things that don’t fit with the model is a pretty good indicator of how well the model works overall. I do think that it is a reasonable assumption that the universe works the same way at the small scale though, and if that is the case anything we’ll find at large scale has to be an expression of these same laws that apply at small scales.