Exactly. Economies of scale + the simple fact of things like a roof for 2+ story block of apartments is going to be far cheaper to replace than a roof for the same number of houses as units.

Wat? Is this skipping the real world of every condominium building apartment owner paying a maintenance fee and having a say in where/how the money gets allocated?

When you rent, you just give the power of choice away and have misaligned incentives (when you own, you give more of a shit than when you are merely extracting profit)

Why can't the owner pay a company to deal with that? You are conflating the part of the remuneration for the landlord that has to do with actual services rendered, with the part that simply has to do with the monopoly on capital rights.