If you dig a canal and charge for passage, that is equivalent to renting a house (and is not "rent seeking" either per economics/public policy discussion).
Most landlords simply purchase, or very often inherit, their property, not unlike feudal lords, and then charge rent to live there. We are drawing some very small lines to separate those two.
I should add that I consider it much different if someone builds a structure and then rents it out. I, and most, would not consider that rend seeking, as they created new value in the creation of the house. Simply purchasing land and then renting it out, creates no new value.
Normal investments, stocks, bonds, etc help to create value in that the things they support need capital to be built. Land itself, will exist with or without capital resources. So the things that make capital markets work, do not apply to land.