It doesn't require it, no. Nonetheless, the majority of properties are professionally managed, so it is simply false that most landlords are small-time individu

It doesn't require it, no. Nonetheless, the majority of properties are professionally managed, so it is simply false that most landlords are small-time individual owners doing it themselves. If everything under "individual" and "LLC/LC/LP" ownership were small-time individuals doing it themselves as a family business, we'd expect to see closer to 78% of properties be self-managed, not 42%. The rate of increase of professional management is also pretty high: the 2015 survey had 43% of properties professionally managed, which had risen to 54% by 2018. I'd be willing to bet it's more like 60%+ now as there's been quite a bit of buying into the rental market by large investors.