Property management is about 15% of revenue, which if you have a mortgage will eat all of your cash flow and 40% of your cash flow after taxes, insurance, hoa and maintenance if you don’t have a mortgage. I do just fine managing myself - more than fine actually - lower vacancy rate (usually just one week between properties), usually no damage to the place ever, and never had to evict anyone (currently have 6 rentals).
Property management is only about 5% of my revenue. Rental rates are high, here.