Not clear to me that is the right approach, or if owning rentals should be more of a fixed income approach (or even speculative - profits only come from the sale of the property).
This actually works unless you inhibit the construction of new units. Naturally that's what we've been doing, which is why it isn't working. But the solution is to stop inhibiting the construction of new units.
Because the alternatives don't actually work. Unless you can build enough units to meet demand, there aren't enough units. Which means you either have high prices which suppress demand because people who can't afford them are forced out, or shortages because you're imposing some inadvisable price controls and then instead of being unable to get a unit because you can't afford the rent, you can't get a unit because they're all occupied and no one is adding more.