[datavirtue]

Build an interface with selectable color themes in both light and dark mode. Not trivial. You have to come up with generalized keys and a style guideline that's followed by everyone everywhere or the user changes theme and suddenly can't see a panel on that one screen buried somewhere.

Themeing is hard. And he is rightly bitching about all the apps that slap on dark mode at the end and leave all kinds of visual bugs in place.

Nothing about UI/UX work, no matter what platform or framework, is trivial. It takes a gruelling amount of work and time, that's why most modern UIs suck hard. People don't have the time, money or skills to do it.