ᐅ Controlled residential ventilation: Number of air supply and exhaust vents

I am a bit surprised by the large number of inlets and outlets often recommended for the mechanical ventilation with heat recovery (MVHR) systems. Almost every room is equipped with one or the other. In some discussions, there is even debate about whether a mechanical ventilation system is necessary at all. I would have thought that two inlets in the bedrooms and living room and two outlets in the kitchen and bathroom would be sufficient for a 120 m² (1,292 sq ft) apartment housing two people. Is that not correct?

Rooms without a valve or not used as overflow areas are not ventilated.
Obviously, it makes sense to have the ventilation system ventilate the entire building …