All I said was that my mum has a house made entirely of concrete and the noise insulation in that house is insane, you can't hear a single thing from room to room. I'm not a structural engineer however and I have no idea why that is.

Oh. Ok. So you have 2 facts sitting right next to each other that are completely unrelated. One about the construction of a building. The other about sound transmission withing the house. I understand. I was under the impression that you were trying to suggest that one fact implied the other. Forgive me