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?