I agree that immediate-mode is a pleasant mental model, though I've heard mixed things about performance. It does a ton of potentially redundant work (though maybe memoization could reduce that), but it removes so much complexity that there's a genuine trade-off. I'm not sure how things shake out in practice; I haven't used it for anything real.

Though the bigger reality for most front-end devs in 2021 is that most of us are building for the web, and the web doesn't really allow for immediate-mode