> Swift should have been a modernized Objective-C. It should have kept the best parts of it, which made it a joy to use, and leave the archaic and the weird things behind.

That's what Objective-Smalltalk is, or rather, what it started out as.

https://blog.metaobject.com/2019/12/the-4-stages-of-objectiv...

It has now gone further to actually implement Brad Cox's idea of a "Software IC", by taking on ideas from software architecture and metaobject protocols.

https://2024.splashcon.org/details/splash-2024-Onward-papers...

> SwiftUI, should have been a rendering template/library integrated with UIKit.

Do you mean it should have used some sort of XML-ish/HTML-ish templating mechanism? For Interscript, I keep looking at that approach, but so far haven't gone down that road (except for HTMXNative, but there it actually is HTML, so...).