For example, I just recorded myself tapping on a product in the Product list screen and the delay between the pressed state appearing and the first frame of the screen transition animation is more than half a second. The animation itself then takes 300ms which is a generally accepted timeframe for screen animations. But that half second where I'm waiting for the app to respond after I've tapped a given element is painful. UX studies indicate 0.1s as a number where an application no longer feels instantaneous. (https://www.nngroup.com/articles/response-times-3-important-...)
Contrast this against something like the Slack app where the screen is navigating even before the pressed animation has appeared. Or for an app with probably not as much engineering focus, Fastmail, which begins the screen transition within 100ms of the pressed animation state appearance.