[jshier]

Suggested? It's required, otherwise behavior is undefined for many APIs. And with the main thread checker you now also get runtime issues when you access such APIs.

It's more shocking to me that Apple hasn't explicitly shifted at least some of its UI frameworks off the main queue in the last 15 years, especially as they've added tools to make it easier. Of course, given the bugs with the parts that are off the main queue, especially in SwiftUI, perhaps that's a good thing.

[kridsdale1]

ComponentKit for Facebook was explicitly built to offload as much ui work as possible to other threads (text sizing being super expensive) and only go back to main to say “here is your new react style model”.

I was very surprised that SwiftUI didn’t do this too.