You can't build the equivalent of UITableView (which is a very important component in almost any iOS app) without frame-by-frame scroll events.

How so? Which feature of the UITableView can not be replicated in JS? I'm struggle to think of one. Swipe left/right to remove rows in a table can be done with touch events.

What am I missing?

I think you're not being specific enough. I am claiming they can perfectly be recreated in JS, just not within a mobile browser at the moment.

I do mean within a mobile browser. We have a pretty large app inside Cordova, and I've yet to get stuck where there's something I can't recreate. Would be interesting to see an example where a mobile browser falls short.

Right, but then you're susceptible to animation stutter and you have to reinvent the look-and-feel of the platform, which is extremely difficult.

Exactly. Customizing exactly how a header bar "sticks" to the top when it hits a certain point, cannot be done with any built in browser scroller. The same is true of any animation that should happen in sync with the scrolling itself (think like a parallax fade/scale animation etc).

What most apps need can be done by listening to touch events instead of scroll events. Eg hiding the top bar when user started scrolling down and so on.

I can't even think of an app that has a parallax effect. If your app is required to have complex animations then web tech is not the right tech choice in general imo