[kevingadd]

They're probably cheaper at the small scale - big panel big price - but at the large scale might not be so cheap: Now you have a point of failure for each of those dials/buttons, the housing is more complex/expensive, you need to make replacement parts for all of those buttons, etc. More training for repair technicians, more parts they have to keep in stock. Possibly more damaged phones because each button is a weak point in the phone's housing.

Screen costs trended down pretty aggressively over time so over the course of a couple years it probably ended up being cost-effective even if it wasn't at day 1. If you're already throwing a relatively sizable high-quality panel into your phone making it a bit bigger may not be as much of a bump up in price.

[pdimitar]

Economies at scale. I didn't think of that. Thank you, this was eye-opening.