Is the God of the cosmological argument the God of gaps?

Hello Rabbi.
From what I understand from reading the second notebook, in a certain sense, the God that the cosmological argument proves is the God of gaps.
After all, we rely on the fact that we don’t know things that have no cause, but that’s just a drawback in science, isn’t it?
Theoretically, it could be that the first cause from which everything began is some stone with rare physical properties, from which the entire world was created.
Why is it actually better to invent some new entity (something we know nothing similar to, albeit rightly so), than to say that one of the objects we know created the world, and then it did not need a cause?