I believe part of the explanation for this is that big landlords have more ways to make money off property than just collecting rent over long periods of time due to the way buildings are valued in the commercial real estate market. Building net operating income has a direct relationship to market value; the ratio of these things gives you the capitalization rate, which tends to be known for a given type of building in a given market.
If the unit sits vacant for a while but they do eventually succeed in growing building revenue through rent increases, they don't have to wait out the full breakeven timeline to make money since they can sell it on to the next buyer at the newer higher price indicated by the latest year's financials.
Let's take an example building where the local market has apartments trading at a 3% cap rate. If there are 30 units renting at 1.2k with no vacancy, that's $432k in annual rent. Let's say running this property requires a $80k property manager, $80k in property taxes, $40k in utilities, $40k in insurance, and $25k in miscellaneous expenses for a total of $265k/yr in expenses. The net operating income is $432k - $265k = $167k/yr. The market value of this building to a prospective buyer would be $167k/0.03=~$5.56M
Renting the 30 units at $1.7k (41% rent increase), gross rents would be $612k. Expenses constant at $265k/yr (taxes would go up, but this is napkin math), the NOI is now $347k and the building is worth $347k/0.03=$11.56M .
In this example, a 41% rent increase more than doubled the value of the building. For an investor with deep enough pockets, the $6M of equity created by renting units at the higher price is enough to cover the cost of a long vacancy / rehab process. But they can't get too greedy or the units will never rent and they're just stuck holding the bag on a high-vacancy underperforming property.
These dynamics amount to what is basically a slow-motion flip playing out over 4-10 years. Some REITs do this across their entire portfolio to achieve healthy annualized returns.