Own a house in Austin that we rent out plus somewhat manage my parent's rentals based in San Antonio for 7 total houses.
With low interest rates, it can make a lot of sense. If my austin house wasn't such a steal interest rate wise as started as primary residence for years, I would not be a landlord.
I self managed and have property management co on a few houses. It is all hit our miss. I have not found any consistency in property managers or renters. All properties are around 4/3 single family houses that go middle income. We have tried social good based rentals and also trying to price as high as possible.
None of it matters in assessing the tenant so basically just cycle through tenants until you get good ones then treat them well by not trying to over index in rent increases.
I am sure you can eek out a few nominal % improvements with strong property management but think most returns are based on type of asset you buy, pricing, and cost of capital. This excludes grossly mismanagement.