How do you know God created the universe? How did you determine it is impossible for material processes to be the cause of the universe?
Are you really asking this? The universe is
everything material - forces, matter, energy, fields, laws - material processes cannot occur unless these - the universe - exists, the universe cannot have caused itself to exist and without it material processes are simply off the table, therefore it simply must exist because of a non-material, supernatural cause.
How do you know there isn't a godless cosmos beyond our universe that is constantly popping out universes, or something else entirely that is not a god?
You cannot have a material based explanation for why there are material things, a scheme such as the one you suggest requires a medium with the property that other things can "pop out" of it, but that means the medium itself has material properties and it's presence too must now be materially explained.
There is no way to scientifically explain why everything exists without encountering infinite regress which means it is not an explanation at all because science takes a dim view of purported physical infinities, they are universally regarded as the hallmark of a flawed theory.
Except scientists don't inexplicably create things, they investigate reality & share their findings with us.
Scientists create theories.
There are many things we will never understand, but that doesn't mean a god exists. & saying "God is why science exists, along with everything else" doesn't help us understand anything.
Where did I argue that God exists because there are many things we will never understand? I did not and nor has any other advocate here.
Understanding is important, so try to
understand the problem then - try to
understand a process that caused matter, energy, fields, laws to come into existence before there was any matter, energy, fields, laws - think about this, really ponder it.
If nothing once existed then nothing would ever happen and nothingness, stasis is all there would be. In order to propose a material explanation for anything the material world must already exist by definition else only something non-material, beyond or ken, could have been the cause - God.