I have lived about 40 years beneath ceilings and never personally taken a preventative measure. I allow my kids to walk under not only our own ceiling, but other people's ceilings, and I have never asked those people if their ceilings were properly maintained.
I've had a ceiling fall on me once and once to a friend while on vacation. Just because it hasn't happened to you doesn't mean it hasn't happened to other people.
Construction regulation is the preventative measure.
Your home almost certainly has preventative measures, including proper humidity and temperature control, structural reinforcement, etc.
I don't mean that you personally have taken those measures, but preventative measures have absolutely been taken. When they aren't, ceilings collapse on people.
See any sheetrock ceiling with a leak above it. Or look at any abandoned building: they will eventually always have collapsed floors/ceilings. It is inevitable.