This seems to be a popular ‘controversial’ topic. I’ve been using SwiftUI for production applications and games since 2021. I drop down UIKit, Metal, or core animation when needed. But that’s no different than when I was making games in UIKit and would drop down to core animation or glyph renderers written in C etc.

Data Flow: The author claims there’s no way to know when things update. Not only does experience help here but there are profile tools that tell you when and where things are updated. This isn’t black magic. Keep Views small, be careful how you hand around data. @environment is super cool but can have a cascade effect. This was greatly improved iOS 17+ and I wouldn’t support anything older than iOS 17.

GeometryReader: Occasionally I’ll use this. It’s kind of a necessary evil when dealing with certain view complexity. It can also be a sign that you’re doing something wrong.

API Stability and performance: Apple users upgrade. There’s no reason that you should be supporting iOS 17 at this point — even iOS 18 is roughly 2%% of our user base across several apps. I’ve been using SwiftUI without major performance issues but I also don’t early optimize. I profile and fix as needed. One of the early studios I worked for wrote all our games in UIKit as prototypes, when performance tanked we’d switch to the appropriate tools (eg. OpenGL) where it was necessary — like in the core game.

I could go on but in the end just use the right tool for the job, if you’re not proficient in SwiftUI or it isn’t going to work for your cross platform project, you have a lot of other alternatives. For me though, it’s been amazing to work with. I stepped away from iOS programming for 3 - 4 years because I was burnt out using storyboards, dealing with massive view controllers, and all the boiler plate it’d take to get a view up and going in UIKit. SwiftUI roped me back in.

* Quick addition edit: Cross platform for iOS, iPad, macOS has never been good. I’ve found recent updates have made things better to the point of tolerable and it’s nothing like when we had to post-fix an ~ipad to our Nibs — There has never been a ‘glory days’ of cross platform Apple UI libraries.