Kitchen: closed or open? What room layout?

In everyday life, she only came home shortly before cooking from work, his overtime just ends so that he is "already" there for dinner, and afterwards both first hear the sofa calling. Without a kitchen door, you go crazy.

Nonsense. There is a kind of organization that largely prevents such things.
Trick 17, by the way, is to start with an emptied or almost empty dishwasher. For that, you can also use the programs for half loads, so that no dirty, three-quarter-full item is standing around at the wrong time.
Then during cooking, immediately load in the stuff you have finished using. Tadaa... and no, it neither takes longer nor does it involve more work than other approaches.
If there is no time to cook for professional reasons (which can certainly be the case), it is missing just the same in a closed kitchen.

To the OP: Definitely an open kitchen. Communicative, decorative, and not necessarily a negative eyesore after cooking. My opinion.

When you cook together socially, you also have peace for it. In everyday life, she only came home shortly before cooking from work, his overtime just ends so that he is "already" there for dinner, and afterwards both first hear the sofa calling. Without a kitchen door, you go crazy.

You seem unable to imagine that other people have different lifestyles. With us, everyday life runs smoothly, it's all a matter of time management. Just because you apparently organize things differently there doesn't mean you have to generalize everything. Even after an incredibly long workday, I wouldn't think of chilling on the sofa before the (for me) everyday tasks are done. Above all, we want to set this example for our children. You can like it or not, but there is not only your way....

Fitting quote from ypg:

"Instead of criticizing every statement here: just answer the OP's question instead of hijacking the thread @@11ant

After several attempts, we have now found our optimal kitchen. A large island integrated into a 60sqm open-plan room. Right next to the island is a large dining table.

That sounds exciting. Are there any pictures of it by any chance?

Appropriate quote from ypg: "Instead of criticizing every statement here: just answer the TE's question, instead of hijacking the thread @@11ant

No, not appropriate, because I answered the TE's question in #6:

If you want to sell your houses not only to Meiers OR Müllers, but to Meiers AND Müllers, then in the future there will be no way around remaining equally equipped for open kitchens and closed kitchens.

For Meiers or Müllers, you can also substitute Tego12 and 11ant here. Any number of people with different attitudes have their attitudes regardless of who wants to sell them a house. I see no trend that your or my faction will convert all dissenters, and therefore for a provider the necessity to have something for both factions in the program.

The question was, however, 'What do you prefer?' and not what we believe to be economically sensible business conduct.

The question was, however, 'What do you prefer?' and not what we believe is economically sensible business conduct

But that is hardly separable: I personally prefer to buy a house with a closed kitchen. But if there are warranties and the manufacturer then goes bankrupt because he only catered to people with my taste, I do not like that. In that respect, I want the manufacturer to also cater to people with other tastes. Indirectly, that is practically in my interest.