It’s hard enough to be cash flow positive with rental real estate for a single property. Especially when you consider the 75% occupancy rate that is considered the industry norm - at least when you go for a bank loan and need to count it as income - then you have the normal repair expenses and prepping for new tenants.
Then you add on the cost of a management company - 10% of rent + up to 50% of the first month’s rent. The only people who I know that can stay cash flow positive are those with no or a low mortgage and/or are very hands on with maintenance and repairs.