I don't rent - I own my apartment. I've invested in a property and a neighborhood zoned for a specific purpose. Cities are generally configured with zoning laws designed to preserve a certain standard of living for the larger community that extends beyond just a single apartment or building. It helps to preserve the intended use of those properties for people that choose to buy in those neighborhoods.
For instance it gives property owners in a residential neighborhood an assurance that a neighboring building can't decide to convert their rooftop to a nightclub potentially disturbing the neighboring buildings with noise, foot-traffic, car traffic, drunks, trash, fights, etc. If you gave individual landlords the right to make these decisions without wider oversight, you'd run into a lot more issues like these. Sure - today they can petition to override existing zoning regulations and that sometimes happens, but residential issues are larger than just an individual apartment or building.