I do know what I’m talking about and the parent post is correct.

Almost all mid-rise or higher buildings built this century have corridor air pressurization units (make-up air). An MUA has a powerful fan, a heater and sometimes an air conditioner to provide fresh, tempered air for the entire building. The air is forced under the doors of the units and leaks out of the building through the bathroom fans and range hoods.

If you live in a tallish, newish building with corridors and you’re getting air from your neighbour’s apartment then something has gone genuinely wrong. Their apartment may be better sealed to the outside than yours or your apartment may not be getting enough pressure from the hall but it would be difficult to have this happen.

It sounds from your description like you don’t live in such a building because you describe the units as having individual exhaust outlets on the roof. That’s unfortunate for you but even if it’s a problem for “the vast majority of multi-family buildings”, the buildings that do have pressurization are much larger with many more units.