The other thing that bums me out about cross platform “solutions” as a fellow UIKit/AppKit dev is their lowest-common-denominator design, making them incapable of the features that make each OS unique and interesting. I’d like to see the opposite approach, where if platform A was missing something that platform B had, the framework would instead fill the gaps and provide that capability on platform A too. At least for me that’d make cross platform development a good deal more pleasant.

As you noted, a robust set of widgets and capabilities out of the box is important too. The miles-long dependency list that comes with the typical JS app stack is unappealing at best, and nothing is worse than having to hunt down an implementation of a widget you need only to find that the 4 options available all have huge holes in functionality in different places, with 2 in some state of disrepair and 1 not being suitable for your project for some miscellaneous reason.