"The steady leak of its best workers to direct employment arrangements with its own (now former) clients." This is a huge hurdle in any direct services market. While you're not likely to hire your own private driver and thus end your working relationship with Uber, you're probably very likely to find a cleaner that you like a lot and who does a great job cleaning your house and go on to form an exclusive working rela…
It might work as a platform where they only take a cut of the first transaction. But, you’re still stuck with high customer acquisition costs and minimal repeat business.
The other option is to directly higher the cleaners so they don't defect. But, then you’re just running a cleaning business and competing with those who have minimal documentation.