The rest of this is just be venting for therapeutic reasons. Ha.
First... you really don't make that much money off the property. Once you pay for maintenance upkeep, and taxes, and taxes on the income you get as rent... you just aren't making much... if anything from the renters. I'm probably losing money on my renters... but I make it back (in theory) in property value gains.
Second... holy hell, some people just should never leave apartments. And all the stereotypes are true. You have to assume they are all out to fuck you over... and incompetent... if you don't, you'll be in for a lot of disappointment.
I rented to an Indian family for 12 months, and after I had to have the place scrubbed top to bottom, ducts all cleaned... and it still smelled like curry. New tenant was furious at me for "not cleaning"... I have no idea how to get the curry smell out. I spent over $2k in professional cleaning services... over 2x what it cost to de-cat-pee the place... now I never want to rent to another Indian family. We literally hand-washed the walls, twice... Then eventually repainted everything inside (another $4k)... the house has no carpets or curtains... no clue how the smell stayed. And I had to give a discount to the new tenant for 4 months because of the smell. There is a fan over the stove... but it clearly never got used when they were cooking.
I rented to a Chinese family for 6 months... and I think they moved like 10 people into a 3 bedroom house. I only met the first couple... but every time I went there were 2 cars in the garage, 2 in the driveway, and at least 4 on the street. And every time I would knock on the door a different person answered in broken English.
Families with kids... will trash your property. And they will bitch and bitch that things were broken before they moved in, their precious snowflakes didn't burn parts of the walls, or drill holes, or kick the drywall under their desk so much it cracked all up the wall...
Pets are disgusting. Cats stink. Dogs are destructive. I had to re-do the wood floors after a tenant's dog clawed them all to shit... had to sue the tenant for damages. "It's normal wear and tear!" they insisted... but they had a 120 pound dog whose nails they never bothered to trim. I got smart and just replaced everything with tile after that. For a rental... just pretend you're dealing with malicious jerks who are bent on destroying anything nice you put in the house... and then plan accordingly.
Tenants will lie and lie and lie again to get out of paying for damages. And worse than lie, they do shit that makes it hard to find the true damages... forget toothpaste in the walls to cover up nail holes... I had a tenant put duct tape over drywall and then use spackling paste and paint on top of that. It looked just good enough that if you were in a rush you may have signed off on his move out damages. I had another family try and prop a closet door up, one that took out the inner glass of a window so it wouldn't appear broken (still had the outer glass) -- but then it made it a harder job to replace the glass because they had bent the frame all to shit. Cost them more than if they would have just told me about the break in the first place...
They aren't at all honest about what they fuck up, and they don't have a clue what it costs to fix something correctly. "Man, faucets only cost like $40 at Costco... why you charging me $500?!" Well... because the faucets you destroyed were nice faucets that cost around $350 each, and there's an installation fee... and I'm not even charging you for the other faucet that I have to replace so the two will still match in the master... I'm also covering the damage to the granite counter top where you hit it with a hammer or whatever when you were trying to tighten your vice grips on the faucet handle instead of calling me when you initially broke it a year ago..."
Tenants always sneak in dogs, cats, extra roommates... My first lease agreement was 10 pages... the last one I used was about 45. It spells out everything that I know to include... plus penalties... "Don't sit on the damn roof, asphalt composite shingles are not meant to be walked on when it's 100 degrees outside... you're getting charged for replacing 1/3rd of the roof because you put lawn chairs up on the roof and literally were up there so often you wore a path in the shingles..." "Don't smoke in the house, but if you are going to smoke in the house... don't just cut the wires to the smoke alarms and just tuck them back up in the drywall."
Despite hiding all the shit they do, and bitching about things they notice... most of them are incompetent at owning a house... won't report water on the windowsill leaking in right away until there's rot in the wood and the whole frame has to be replaced... won't report a wasp nest growing out of the rafters in the roof until it's a $1,200 job to remove it... will let their kids hang off of the ceiling fans and fuck those all up... Some people should never live in a house... put them in an all brick apartment building with cement floors and reinforced windows. There's a reason public schools are built the way they are.
You lose so much faith in people when you rent property. If you don't assume they're all out to fuck you over... you'll get fucked over. It'll cost you a fortune in repairs, and so much hassle and stress because the dipshit who rented from you will fight you tooth and nail... and cry about every little cost... when in fact they aren't even paying 50% of what it really cost to get it repaired... let alone the time you lose because you can't rent it in the shitty condition they left it in.