You don't need to explain it to me, I'm paying a mortgage and have rented before. But a rental isn't a mortgage. You don't get your money back when you return any rental item, why would a property be any different?

The landlord is offering a service: a property that you can move into almost right away, sometimes even furnished, with little risk and without having to manage the property. They're the ones who have taken on the risk of taking on a mortgage or have spent a lot of money buying something outright.

I'm not defending all landlords here, but the concept. I think rentals are an important part of the market and for social mobility.