[darren_]

> How is implementing dark mode even remotely comparable to launching a new general purpose CPU and transitioning an entire product line from one CPU to another?? Is changing the color on a web site that hard?

They're definitely not comparable, but having been involved in implementing dark mode for an iOS app (the quote you're reffing is talking about the mobile app, not website): Yes, implementing dark mode for at least an iOS app can be surprisingly challenging (or at least, a lot of work). It's probably much easier to write a brand new dark-mode supporting app, but retro-fitting it onto an existing app is a whole other thing.

Your designers need to re-colour the entire UI (and this turns out not to mean just "Map colour X to colour Y" btw), you need to cope with on-the-fly switching (iOS devices can be configured to switch dark mode setting automatically at sunrise/sunset), anywhere you're doing custom drawing needs to have dark mode retrofitted into it, and if you're getting imagery from a backend anywhere you'll probably need to add support for getting both light/dark mode images at once (which of course also means you need to re-draw all that imagery for dark mode as well). There's bound to be more stuff I'm forgetting.

So yeah, dark mode for an app can be a bit of work, it's not just swapping colours.