Ventilation in new buildings (central vs. decentralized), noise disturbance

Here you can still read quite a bit about the topic:

Even features like summer bypass: are overrated

Well, the system does help because it independently opens or closes the bypass (e.g. at night, when the residents are asleep, but at the same time it is the few hours when it is cooler outside than inside).

And what good does it do? The effect is negligible because the exchange rates are too low.

An open window does more at night

Normally, the bypass is generally open in the summer... it does help, but it is only noticeable after two nights and if the day in between was not too hot.

A question about the installation of a central ventilation system: does this system have to be installed directly where the pipes go through the exterior wall to the outside, or can, for example, a pipe also be routed through another room to the outside? In our case, the utility room is located behind the guest bathroom, so both air vents would come out on one side of the house. I once read that the air vents should be on two sides of the house (i.e., at a corner of the house), but this would only work if the utility room were also directly at a corner of the house. So, could a pipe be routed through the guest bathroom to the outside?

Best regards
Sabine

Thank you very much for all the answers here.
Currently, I tend to install decentralized devices from Meltem. Three times each over the two-room system, so that one bathroom/WC is ventilated and another room (bedroom, children's room, study) is ventilated. Then a standard device in the living room.
This puts the material costs at around 5k€ and I think the installation can be done very quickly and easily (flush-mounted set --> directly installed into the wall + laying 2-3 pipes).

This way, I have all rooms at least partially covered, meet my minimum requirements, stay within the budget, and do not have to have pipes laid throughout the entire house and accordingly box in ceilings.

Am I being too naive here?
Are the installation costs actually higher so that in the end I come close to a central system, and do I perhaps even need to be careful with the statics when laying pipes between rooms? Or do I need to consider more when installing the fans than just covering all rooms? I think here the details like air exchange rates / air volumes etc. are not fully covered (but as I said, I am not afraid to ventilate with the window if needed).
Also, I can imagine it being unpleasant if, for example, I am sitting in the study and the demand ventilation in the guest WC starts, that suddenly much more air is blown into the study or the fan becomes louder.
Also: do I have to make slots in the individual doors so that the air can circulate between the rooms?

Thank you very much!
Kiri