The rising mains are the real asset
In any older block, the cable running up the building to feed every unit's meter is the thing that matters most and gets looked at least. In a 1970s walk-up it is often around fifty years old and was sized for a household with a fraction of today's appliances.
It rarely fails suddenly. It warms, then a termination gets hot, and the early signs are flickering, one unit dimming when a neighbour's appliance starts, or a smell in the stairwell. It is common property, it affects every lot, and it is the single most worthwhile thing for an older committee to have inspected.