But most of the attempts refuse to take on any liability for themselves, and half the reason to use such a company would be accountability and reduction of personal risk.
For the various home projects I've done before, it always feels like such a gamble with a ridiculous amount of information asymmetry, although thankfully the internet has made great strides in fixing that part of the equation.
The market for contractors is basically a market for lemons. There's 10 bad to downright criminal contractors for every good one, and most customers have no way to judge the actual quality of the work until it's months later and something falls apart.
Some great gentlemen who realized that for skilled-tradesman, the real bottle-neck is lead generation. And more importantly, they respect and treat their partners and customers with the utmost of care and regard.
UT picked them up for a major "refreshment" of thousands of units of campus housing and they've completed some stunning work in the short-term-rental market here in Austin with investment properties.
The last time I talked to one of my friends over there, they were focused on the short-term-rental/AirBnB reworks of investment properties as it was lucrative and exploding.
They've only experienced organic growth from what I know which is really remarkable considering their success so far. I'd love to see them meet up with a formidable equity partner and see what they could do at an even larger scale...
[0]https://www.yelp.com/biz/quick-residential-rescue-austin-2
Once you have the hub relationship with homeowners, you can add however many spokes as you please.
Additionally, houses are an absolutely massive market. Housing is the largest expense of most people I know, and there's a ton of price weirdness. A kitchen remodeling might cost $14k, and that's not something you can buy on Amazon, and it's not like you can get your kitchen remodel done in China for cheaper (well, unless your house is in China.) If you were planning on $15k for your remodel, and a local contractor would offer $14k, but Houzz sends you to a "Houzz professional" contractor that offers $16k, you'll probably trust Houzz and accept $16k without questioning too much.
That's two thousand dollars from one kitchen remodel right there. Of course, that's not how Houzz's business model works right now, but there are lots of ways they can make money. You're also not going to accept that price discrepancy from any other consumer-focused things. Say, a laptop: if the new Macbook was $1600 in Best Buy and $1400 on Amazon, almost everyone would just buy from Amazon.
Additionally, they have a surprising amount of name recognition among the wealthy. I know a decent amount of wealthy people, and a few ultra-wealthy people, and I've heard maybe 25% mention Houzz. If you can get even a tiny portion of the ultra-wealthy-house-spending market, you're golden. Remember, the ultrawealthy have most of the world's wealth, and they spend a lot of that on ridiculously fancy houses with no care about cost.
Finally, there's no "bomb factor". Maybe there'll be a scandal tomorrow about Facebook selling your photos to some evil actor. Maybe Snapchat will get a massive lawsuit about its storage of millions of inappropriate pictures of underaged people. But how are you going to get angry at Houzz?