The profit is compensation for the risk. The mortgage and property taxes and maintenance are due no matter what - can't find a tenant, tenant doesn't pay, tenant flushes paper towels down the toilets every day etc etc.

If there was no profit there would be no landlords. Some might say that's great. But it would be a world with less flexibility, with fewer choices. Don't like your job and want to move? Split up with your partner and need someplace to live? Moved to a new city and don't know where you want to put down roots yet? At college for 4 years? Don't want to deal with house maintenance? "F** you, buy a house anyway". That's what we'd have if there was no rental housing.

> renting to be more expensive than a comparable mortgage.

that doesn't sound plausible. May be for a select few properties that are in some unique circumstance (e.g., the seller of the property would sell underpriced because they needed quick sale).

And often, in arguments like these, the rent is the rent, but the mortgage is purely the interest on the loan, and doesn't count the maintenance cost, and doesn't count the deposit required (which has a cost, ala the cost of capital). If you added up all these costs, it exceeds rent.

You do know that the posters on r/landlord are often selling services to landlords and thus have a financial incentive to make being a landlord seem attractive. Its a pretty safe assumption that reality isn't that rosy.