Landlords derive profit from owning a scarce resource, not from providing any services.
A property maintenance worker does the same thing but is paid for their time like any other working class individual.
This is why you can have a terrible landlord just like any good one. It’s not the quality of the landlord that’s the problem, it’s the exploitative relationship. Just like how slavery is bad despite their being “good” slave owners that didn’t beat their slaves: it wasn’t the treatment of the slaves that was the problem, it was the ownership of human beings.