However, this serves to illustrate: keeping rents high is rather a combination of being bad at mathematics, tacit collusion among landlords and protesting rent control.
But a dramatic drop in rent will result in someone locking in that rate and literally never leaving. Taking that apt off the market essentially forever.
I know a few people with rent controlled apartments in SF who have held them for decades so their rent is impossibly low. They'll never leave. At least one hasn't even lived in SF for many years now but the rent is so low it's worth it to them to keep it as an occasional weekend crash pad even though they live elsewhere.
These things are never as simple as they seem...
I’ve been renting for 8 years and I’m the shortest tenancy in my building (as an example).
And the math about keeping it empty doesn’t factor in the sales price. A realtor explained it to me - if you have a 3 unit building, the sales price can go up by several hundred thousand dollars if one of those units is empty. That could easily be 5+ years worth of rent, so keeping a unit empty for a couple years can be a financially smart move. The reason is because evicting a tenant (owner move in) is a very expensive and lengthy process that few buyers are willing to put up with.