I don't use the new concurrency features, as they are one of the main culprits of this mess. (so stick with 5.x)

SwiftUI is a wreck, that is still not good for advanced UI and you still have to use UIKit for some parts, and

Taking Objective-C, with DispatchQueue, and some modernization of it, and some new data structures, which it need, was all it was needed to make a good new langue.

It could have been Apple's rival to GoLang, but instead it ended up being hydra/monster with too many pardagimns, and none of them are good.