You might be able find some info on the frequency of house fires vs apartment fires if you tried. It's also interesting to pick a local news site, search "apartment fire" and see what comes up - in my area there were a bunch of "1 or 2 units burned, 2 or 3 more damaged by smoke" reports, and the fires that destroyed a whole building were much less common and were unoccupied or known to be in violation of fire codes. So the precautions seem to reduce the risk of your neighbors bad cooking burning your precious stuff up. As to longevity, I live in one that is about 20 years old, and the place creaks just a bit when the upstairs neighbors fill the bathtub. I used to live in one that was about 30 years old but the complete and total lack insulation in the walls made other structural complaints seem silly.