Most if not all modern door closing mechanisms are two stage and adjustable, intended to be rapid closure most of the way, followed by a slower clunk of completion.
Our building’s fire inspectors used to adjust them to one maximum slam, citing “fire safety”. That was until I stood there with my own Allen key (the kind of hex key you get free with furniture from Ikea) and told them, as soon as you’re gone, I’m putting it back how it was.
In the case of your neighbours, probably the easiest thing is to first tell the strata committee about the crack in the wall, and then explain that there’s no point in fixing it until they adjust the neighbour’s door closure (which is also common property).
Two birds with one stone.
You will not be able to persuade people (especially youngsters) to close a door manually when they can just walk through and leave it. But you can have the door adjusted so that it’s no longer a problem.