They just closed a massive round today to continue scaling the business.
I'm not convinced that the in-doctor's-office experience is significantly better with One Medical, but outside the office is quite a ways better. The app makes coordinating everything much more efficient. Instead of calling a receptionist and trying to schedule an appointment, you can see all the openings and book asynchronously.
It's interesting to think that the primary service One Medical is offering (healthcare) isn't even the most compelling reason I will continue to use the service. The prospect of returning to a system where I have to talk on the phone to schedule an appointment is too painful to stop using them.
Sometimes when you're designing products, eliminating pain points caused by competitors, substitutes, or the status quo is a stronger differentiator than than trying to create something entirely new.