They get a few things right, mostly in terms of practice management and pseudo-vertical-integration that make the experience far nicer than a traditional doctor's office. It's nothing world-shattering, but 99%+ on-time appointment starts is a big deal.

Their online platform is very UX-focused. The app is nice and easy to use, and makes things like firing off a quick message to your PCP for an Rx refill super super simple. My old primary care doc had nothing of the sort. It was the old 1990s way of doing things. Try to get scheduled... by phone... a month out... for a refill of a skin cream I've used for 20 years. I get that they want me in yearly, but that's inconvenient and annoying.

OneMedical's practice management/online tool for patients makes scheduling dirt simple. Their offices are REALLY nice. It's a little touch, but it's trying to raise the bar on that. And they offer their own teladoc services as well, which are then obviously integrated into their EHR for your PCP services, so everyone is on the same page.

OneMedical tries to combine PCP with some urgent care services, so they have a same day component, as well as some specialty services.

Just a lot of small but meaningful ways in which they're better than a traditional PCP office. They're also apparently offering practice management and holiday support for existing practitioners, which is interesting from the perspective of the S-1. If their EHR/PMS software is as nice as their app, I imagine that's a welcome change.