You may be surprised how many people can't mentally disassemble basic mechanical systems. I just helped a family member change the handle/arm on their toilet, and they'd been waiting a month for someone else to help. My mom is currently waiting for me to pick up some drywall anchors to re-mount a (small, lightweight) light fixture.
There are a lot of people who don't understand this stuff to a degree where they don't even know whether a repair is dangerous or not. My family member was afraid that if they messed up installing the toilet arm they'd flood their house.
Those people are very capable of having a few repairs a month, just on random stuff. Cabinet hinge screws wore out their hole and just needs a bigger screw, shower curtain mounting is loose and needs new anchors, an outdoor light fixture with a bulb cover needs a new lightbulb and they can't figure out how to get the cover off, etc.
There are a lot of people who don't understand this stuff to a degree where they don't even know whether a repair is dangerous or not. My family member was afraid that if they messed up installing the toilet arm they'd flood their house.
Those people are very capable of having a few repairs a month, just on random stuff. Cabinet hinge screws wore out their hole and just needs a bigger screw, shower curtain mounting is loose and needs new anchors, an outdoor light fixture with a bulb cover needs a new lightbulb and they can't figure out how to get the cover off, etc.