Mobile work really isn't about user interfaces, it's about full application design. Both iOS and Android are platforms which allow you to code out most basic UI

Mobile work really isn't about user interfaces, it's about full application design. Both iOS and Android are platforms which allow you to code out most basic UI tasks "for free" in a way that doesn't really exist in web dev. Complex UIs, of course, can be challenging and unpleasant to write, but one can make a career as a mobile developer spending a very small percentage of their time concerned about UI.