Rent-seeking is nevertheless what landlords are doing via the collection of rent on a leased house, in the cast majority of cases.
If the rent being charged is in excess of market value, there is indisputably a surplus profit being pocketed by the owner, which thereby cancels any contribution back to society (quite the opposite, in fact, since the profit is directly off of the backs of tenants, who are typically not land / property owners).
However - even if the landlord is charging market rate, rent-seeking is still going on when the value of the property has appreciated (say, the whole neighborhood’s property values have gone up) and the owner is charging tenants in excess of what the owner is actually paying (which was negotiated at the time of purchase, when the value was lower) in order to make a profit where the owner has not contributed at least the same amount of value.
Since both of these tend to be the typical case in the landlord-tenant relationship - property value goes up, landlord accordingly raises rent in order to profit off of unearned income (which it is, at least according to US tax law), landlords are absolutely rent-seeking rent-seekers.
And while I sympathize with the plight of the retired granny and grampa landlords whose fatal flaw was trusting their no good, criminal-minded tenants too much - that does not hold a candle to the plight of the millions of working class Americans who will be sleeping in their cars because they didn’t have the foresight to become homeowners.