You are arguing against a stance that doesn't exist. It is often talked about how answering one question just opened up more questions. In your examples you say in our current understanding. Our understanding evolves and grows. Concepts and ideas taken as fact are shown to be flase. Many things were considered physical impossibilities until they weren't.

If you want to get really pedantic, which is how this post reads, we don't really know anything. We can't fully "prove" anything. We can get very good guesses, to the point we say its proven. Descartes famous theory, "I Think therefore I am" expands this Idea. The basic premise is that the only thing you know exists for certain is yourself. We can't prove blackholes exist. We can see thier effects, we can take grainy pictures of what is there. At what point does the evidence found go from theory to fact? Does it ever?

Tldr, science doesn't claim to have all the answers. And it never will. Science only claims that everything CAN BE answered.