You are assuming people actually make money on rental properties. I have had 3 rental properties and you don’t make a profit until the mortgage is paid off which is practically never. What you propose would hurt more people than it helps.
You are building equity - maybe your monthly profits are 0 early on, but your total value is increasing m/m. You can sell your rental property once your mortgage is paid off. If you back calculate your monthly profit is essentially ~ (selling price) / months owned.