Well said Andrew! While my main role is ensuring to deliver backend APIs and architecture, UX/UI is critical in any sort of client application.
Because you can have a great product internally, but if it's not well presented or it's confusing for people to use, then they're not likely to truly benefit from it. Let me share an example with you:
Gran Turismo 5 is a great game, but often its UX is place as a wrong example of introducing user journeys, due to the amount of menus and visual clutter. On the other hand, games like Burnout 3:Takedown have a really intuitive UX and all the actions the user should take to start a race.