I realize that I may be in the minority here, but I used to be a landlord. I never charged full market rate, and I always took care of my tenants. I never kept any security deposit money. One tenant had a breakup, and I showed up that evening with a locksmith to change her locks so he wouldn't be a problem. That cost me some money but it didn't cost her anything. I mean, they're paying for service you need to provide service.
And because of that, you made less money. A bastard landlord would make more money and be able to invest that money into buying more properties. Those properties would bring even more money, allowing them to buy even more property and so forth. This dynamic is why the vast majority of landlords (and capitalists in general) are bastards.
Capitalism is a system where the selfish and greedy will always triumph over the selfless and charitable. It is designed from the ground up to incentivize selfish behavior.
You did it right, but the only thing keeping most people honest is regulation. Until pro-tenant behavior is properly incentivized for landlords, most will remain shitty and selfish.
There are laws around renting. It's not a free for all, at least, not where I come from. There are cases where humanity acts with generosity. This argument works both side and it's unproductive.
Sincerely thank you for being a good person in a harmfully flawed system. You probably won't get rewarded for it. Most likely you'll be punished for it. But someone out there probably thinks you're pretty cool for doing it.