They're also used as cleaning tips for small/targeted applications, especially when you don't want lint from a Kleenex or paper towel lingering. Makeup application/removal and electronics cleaning, for example.

I think (not a doctor) the ear thing is because if you go too deep you can cause some serious damage, and they can make wax buildup worse by compacting it. If you stay close to the ear opening, and do circular motions to swipe wax away, and clean your ears often enough that you don't get dense wax build up, and don't "double dip" to introduce potential pathogens, then I think they're pretty safe to use? But that's too many caveats for lots of people, so I think ENTs often deal with people damaging themselves with them.