“ feature gaps between platforms, making their feature set a union of features” This fundamentally doesn’t work for UI/UX. You have to pick a paradigm and impl

“ feature gaps between platforms, making their feature set a union of features” This fundamentally doesn’t work for UI/UX. You have to pick a paradigm and implementation details at some point and the high level UX design of Windows UI dejure and Mac are just different, in ways that cannot be factored out of a framework without leaky abstractions. Your choices are: the Qt/Tk/Swing approach write once, a solid if dated UX that is themeable but not truly native anywhere, the web app (or its QML/Flutter/FX equiv), wxwidgets etal which sort of tried to be native everywhere last century and looks and works that way, or at least two parallel independent native UI implementations which is a gargantuan more effort. Or go whole hog with FLTK or your own custom thing. a11y? WTF is that? “ Instead they typically take a least common denominator approach, limiting apps written with them to only the most common basic features.” I wouldn’t call wxwidgets basic, but it is a mess. It can’t be any other way. If it could someone would have made it in the last 30 years. Just because you use Cocoa/AppKit rather than drawing on a canvas does not magically make your app feel like a Mac app. Literally 100s of side projects have started down this path. People eventually learn you can’t abstract everything away, at least not the labor intensive part.