[mandevil]

They aren't really in the business of fixing up a home, as other people have already said. The analogy for what they are trying to do is more like high-frequency trading (as the amazing and invaluable Matt Levine has pointed out for years).

When you want to sell 100 shares of Company A, and someone else wants to buy 100 Shares of Company A, sometime you do so at just the same moment, and you can directly transact with them. However, almost all of the time you are selling and they are buying a few minutes apart. So called "Market Makers" (aka "High Frequency Traders" aka "Flash Boys") take the other side of both transactions, and get a very small cut (generally less than 1% on the modern stock market). They are basically in the business of time-arbitrage. Their goal is to almost always be net zero on the market- to have roughly the same number of buys and sells at any given moment, so that the market floats along smoothly and they make their tiny cut whether it is going up or down.

And so the home buying version of this is, it is a real pain to have to find a buyer for every seller at the exact same moment. If we could similarly have a market-maker who can buy houses and sell houses when someone comes along looking to be the other side of that transaction, wouldn't it be awesome? You could take a tiny cut of the transaction, but what a big transaction! Just for some time arbitrage. Of course, the differences are stark: shares of stock are fundamentally fungible, whereas houses are almost as non-fungible as one can get. Stock transactions are quick and painless, and don't require months of work by teams of mortgage originators, with inspections and appraisals etc. It is difficult to be net-zero as a market maker in houses, since your inventory sits on your books for months and months, either appreciating (yay!) or depreciating (boo!). All of these are serious problems with the business model. The current wave of companies attempting this basically said "what if we fix this with <waves magic wand> Artificial Intelligence?" The actual answer is that they have once again found themselves in the business of picking up pennies in front of a steamroller- the fate of all arbitrage attempts that blow up.