`NSTextView` is good. My point is not that `NSTextView` itself is bad. The problem is that once you are working with all the "modern" Apple stack (Swift, SwiftUI, and the direction Apple is clearly pushing developers towards) `NSTextView` does not fit as naturally anymore. Some newer APIs are not even available for AppKit now, so you quickly end up in an awkward middle ground.
By "streaming" text, I mean a formatted text stream that has to be parsed, formatted, and appended on the fly - basically how every model/AI chat works now. And this is where `NSTextView` becomes tricky. It forces an interesting architectural choice: either go deeper into AppKit with `NSCollectionView`, custom cells, manual layout, etc., or fight the whole SwiftUI model by embedding something like `NSTextView` inside `LazyVStack` / SwiftUI views & then dealing with all the integration problems.
So I am not saying Cocoa / AppKit was always bad, or that `NSTextView` is useless. I am saying that for modern chat-style UI with incrementally rendered formatted text, it does not compose well with the rest of the modern Apple stack.