I'm sorry but this flies in the face of my experience. Most landlords I have met buy properties and then outsource their administration to property management companies. I have never seen or spoken to my last three landlords, none of whom lived anywhere near the same city as the property.
Landlordism is parasitic in the literal sense of the word. Landlords get rent and capital appreciation for doing nothing but possessing an ownership title. The propertyless pay the propertied a premium to live.
In light of both those observations, I would say any enrichment in this case is "silly", and that landlords don't tend to do much - or any - work.
>"If it were so profitable, then tons of capital currently being spent on other uses (tech, medical, finance) would instead go into buying up more housing."
This is a non sequitur. If X is profitable and the market knows X is profitable then it should, in theory, be attracting exactly the amount of capital it merits already. In the UK, where I live, the rental sector has exploded, jumping from 2.8 million households in 2007 to 4.5 million in 2017. [1]
[1] https://www.ons.gov.uk/economy/inflationandpriceindices/arti...
