Isn't that basically what SaaS is? Companies that would have had to hire engineers to do bespoke work can contract out to a SaaS vendor and get what they need for a fixed fee.
SaaS doesn't make sense every case, just like Redfin doesn't, but it's still valid.
Those SaaS vendors are still paying developers; if a cookie cutter self-service model works for your needs as a customer, more power to you.
Rarely has that appeared to be the case in the dozens of real estate transactions I've been through, and it might explain why Redfin can't grow faster; people want to have their hand held through the largest transaction of their life, and those who can charge more for those services will.
Meh, at some point, it always becomes a matter of perspective. If the same work is getting done, then you just shift around who does it or how it's paid for.
Rarer, but more valuable, is discovering new work to do, or old work that doesn't need to be done, and then either inserting it or taking it out of an existing market/process/role/job/company, while still managing to get paid for your own contributions.
SaaS doesn't make sense every case, just like Redfin doesn't, but it's still valid.