Gypsum plaster is actually the more ecological and compatible building material... Gypsum plaster is also the opposite of tight and dry – where have you been getting your information for weeks? If a plasterer says he doesn’t use that crap, it’s probably because he can’t handle it; lime-cement is much easier and cheaper. Gypsum has the property of regulating moisture, which is less crucial with a controlled residential ventilation system (which is mandatory nowadays) but still offers advantages. If the house is too dry, that has nothing to do with the plaster. But in the end, 90% just slap a DIY store dispersion paint on the walls anyway, so it doesn't matter what’s underneath. Just as important is the choice of paint, so what’s planned there?
That is factually incorrect.
Gypsum plaster is cheaper and the classic mass product. It goes quickly and is easy to work with. Lime-cement is more expensive and considerably more complicated to apply.
Gypsum is not tight; I know that it is proven not to be more airtight than lime-cement.
It’s more about the perceived climate. You have to be receptive to that, that’s clear. Many don't care.