Suppose you want to buy a house. The idea is that, you'll agree on a price of the house, which is greater than current market value. Suppose listing price is 100K. You agree on 150K with the lender. Each payment is expected to pay as part of 150K.
This however creates two problem. Lender's profitability depends on accurately determining the future price. Either lender or applicant can suffer from imprecise price.
An alternative I've seen is, the notion of rent. Suppose, at closing the lender buys the house for you, with the intention that you'll reside there and pay market rent.
Suppose the price of house is 100K, and rent is 1000/month. Now suppose, there's no down payment, you'll have to pay above 1000/month to start building equity.
After first payment of 1100, you have equity of 100$, while the lender has 99.9K. So, when the 2nd month payment goes, you can get to keep 0.1% of rent as equity OR use that to build more. Over time, you'll eventually pay it off. This part likens it to interest, except because rents are market based, they don't fly with borrowers.
So lenders have come up with "Administrative" fees, which I equally think are BS. Hence traditional mortgage still are more accessible.
I would love it if there was a rational product out there.
Wait, what ?
Other than that, they're essentially "pulling an uber". They're significantly riskier investment schemes that most institutions have had really bad experiences with a few decades ago. They're ignoring regulations that exist for good reason, and regulators seem to let them for some reason (for now).
If you want to do that, great. Risky investments are most often the mispriced ones (cheaper then they ought to be). But please, do it yourself, figure out the risks, and don't let some institution do it for you with the promise of cover or ... or you will regret it.