In states I've lived in with property tax there is a homestead exemption for the house you live in. In my current state that's about twice the tax.
The effect: Rent goes up to cover the tax and margin is added, so the rent goes up more than the tax.
>Rich investors and companies effectively get to buy homes at a discount vs average joes.
Usually the difference is that the big investor bought the property at lower price, and your rent is based on the lower valuation. Annual rent increases are usually are much lower than market increases - there's a lot of value in keeping a tenant year over year.