On-demand? There are a lot of scheduling difficulties. Getting a sex worker on short notice, even in a popular and mostly-legal city is a nightmare. And it runs into the Airbnb-pre-instant-booking issue: You contact several people, they don't all get back right away. Then an hour later, you have several replies, and since you can't book them all, some end up annoyed you're wasting their time. Not to mention any screening issues or other deal-breakers.
And if someone does have some last-minute availability? They can't easily fill that slot. It's hard to just offer sex work in a few hours here and there - you'll spend all your time answering phones.
But it isn't just the "Uber" aspect that we're working. Sex workers lack cohesive unions and shared resources. We'll be able to pool for things like security agents. We can handle client verification one time and be done.
We'll do photography of workers, then advertising and bring clients in. This benefits less entrepreneurial workers that don't want to try to manage an online presence, deal with SEO, try to A/B test their photos and copy, etc.
There are other similarities. Uber had to avoid LE, so do we. Uber has to deal with partial cash payments and reconcile, so do we. Uber offers some insurance, so do we (legal). But we'll be far less sexist than Uber, that's for sure.