Red lime plaster added value? Which color and how often to paint?

Yes. There is the possibility to improve the margin. Hype. And eco sells well and hardly any builder really questions it technically. Especially since gypsum plaster is also somewhat "breathable," meaning it absorbs and releases water, just not as much as lime plaster.

I just wonder why the topic is so current in new constructions as well? Just a hype?

Gypsum is simply too paltry and cheap. It has to be breathable, ecological, and trendy. So also more expensive, without you feeling, seeing, or breathing any added value.
I see no objective reason to use more than gypsum plaster in normal new constructions. In the bathroom, I would still tolerate it, but even there gypsum works without problems.

Damn. 99% interpreted correctly. :D Yes, I am really quite stuck and would have liked confirmation here that the added value of the plaster really covers the extra effort and is not just a marketing gimmick.

I guess 7-11 years higher life expectancy WITH this great special plaster.......... but if you can't afford a decent sofa after these additional costs, those gained years can also become a torment. :D As I said, better, more or greater is always possible.