> Is it because the perceived alternative is another run-off-the-mill Electron RAM guzzler, because there aren't any _good_ GUI widget frameworks?

Yeah, I think that is 90% of it. And the whole related ecosystem aspect. All the major ways of building GUIs suck right now, especially for tiny apps. And to further exacerbate the problem, GUI frameworks are generally tied to their programming languages, Qt is C++, SwiftUI is Swift, Flutter is Dart so on; spewing some terminal escapes to stdout is something that can done from basically any language with relative ease.