Why isn't there a way to make near-native desktop UIs that's similar in ease to browser and electron UIs?
it seems ridiculous that we have to embed an entire browser, meant for internet web browsing, just to create a cross-platform UI with moderate ease.
Why are native or semi-native UI frameworks lagging so far behind? am I wrong in thinking this? are there easier, declarative frameworks for creating semi-native UIs on desktop that don't look like windows 1998?
It depends on just how "cross-platform" you want to make it. If you came up with another standards-based UI framework that had the same cross-platform penetration of web browsers, then you'll have effectively reinvented the browser. For everything else, you can basically pick a maximum of two: cross-platform, native, and easy.