The business in this case being what? Landlords didn’t create the land, nor did they build the residence, nor did they improve its value by building a community around it. They are benefiting off of the work of others simply because they “own” it. The most common arguments I hear in support of landlords are:
Landlords take care of maintenance. Maintenance costs don’t increase 20% a year. If rent was simply maintenance costs it would be a fraction of what it currently is
Landlords allow people who cannot afford a home a place to stay. Why do you think they can’t afford a home? It’s like saying without scalpers people wouldn’t be able to see concerts because the tickets are instantly purchased by bots.