You can actually be a good landlord. In theory. But at the point where you actually become a good landlord, it's more of a public service than something you actually make money on.

Are you the same person that always claims they know very nice police officers whenever someone says "ACAB"?

Your lifetime of experiences does not consistute a meaningful sample size when compared to everyone else's. It can leave you feeling or believing something completely different than everyone else, for good reason, but that doesn't make it true.

Most landlords own property because it is a vehicle for wealth growth. And if someone owns something because it makes them money every year they are likely attempting to or interested in maximizing that return. That means cheap maintenance, little to no improvements, and an increasing price tag like an investment vehicle instead of a decreasing price tag like a consumable good.

If landlords were systemically good, if the overwhelmingly majority of landlords were good, rent would go down every year as the building and utilities get used - only going back up after real meaningful renovations.

My last flat had an awful kitchen design, very aesthetic but a nightmare to actually cook in. Can you imagine living in your own home and hating something you Interface with everyday multiple times and not changing it despite knowing you have the money and skills to do so? I can't. But because I have a landlord, because people have landlords they are stuck with the decisions of someone who either makes absolutely or relatively bad decisions all the time. My current flat the bathroom is a nightmare to live with because a quarter of the room is a bathtub and yet there's no place to put your toothbrush or plug in a water pick/hair dryer/razor. I'd happily change the entire bathroom, renovate it to include a decent sized shower, add electrical outlets and kitchen sink that isn't just a bowl - but again I can't because that isn't putting money into my landlords pockets and because they're not planning on living here ever again (if they ever did) they don't care how it is to live in. That's what being a landlord does to someone naturally, it's understandable but the reality is you care less about a place you're not living in, you're spending a lot of money for a place you're not living in so you want to make that money back so you can improve the place you are actually living in so you're naturally getting more stingy and cheap at your other properties, and over time the incentives of the system realign your values and behaviors.

No, I don't think your lifetime of "good landlord stories" is a meaningful data point to change what the overwhelming majority of people experience every day of their lives nor the systemic logic/reality of the situations. Good people can become landlords with good intent but they can't stay good and be a landlord because being a landlord is inherently an anti-productive thing to be in society - overtime the incentives change people into doing things that hurt others for their own interest.

I think you're mixing up "there are bad landlords" with "landlording is bad". I'm sure there were good slave owners as well but it doesn't mean slavery was good. In someways landlords are modern slave owners. They can treat you humanely but at the end of the day they're taking a slice of your money just so you could have a roof over your head.

Hypothetically, if tomorrow your government would say that whatever house/apartment you live in right now is legally yours to keep would you miss your landlord? I very much doubt it.