I put 100 watt bubls in my kitchen ceiling fixture with 3 globes keeping the heat in, and over a couple three or 10 years, the plastic around the metal sockets got brittle and fell off in chunks. One socket stopped working too, bad wire connection at the metal socket.
I also used a 100 watt bulb in a desk lamp with a cone shaped metal shade, and iover a couple years it damaged the socket, but in this case the built-in switch. The kind of socket that is colinear with the rotating knob that is the switch, (like is used in over the bed headboard lamps with the long salami shaped bulbs) I have to grab the round thing hard and trun hard, to go from on to off and offf to on. The next two notches, which are the same thing are easy, but that makes a full revolution, and the next 2 are very hard again.
No fires. And this is 100 for a 60, not 75 for one (the ceiling fixture. The desk lamp may have been designed for 75)
BTW, the lamp is probably 50 yeaers old and will last another hundred after I replace the socket/switch. During the really hot weather I had to start using CFL in it or it was too hot to get close too, but the switch was damaged already.