It is not just individual apps UX; the growing number make it more of a problem.

"Two of Apple’s earliest designers lambasted the company, which they say was once “a champion of the graphical user interface,” for abandoning “the fundamental principles of good design.” They say that in its quest for beautiful design, Apple created “obscure gestures that are beyond even the developer’s ability to remember.” And if a developer doesn’t find them intuitive, what chance does a late-adopter stand?"

Entefy Blog Nov 02 2017

Simple, fast and functional UX is a priority for all digital platforms. But- 

"That’s a problem, because as everyone becomes more reliant on technology for everything from buying groceries to accessing medical care, poor user experience design excludes people from important services. It’s also short-sighted from a business perspective, since a middle-aged executive likely has far more buying power than a smartphone-savvy teen. Yet many of our most commonly-used platforms seem to disregard usability factors for all but the youngest consumers."

Effective digital platforms address this issue from day one.