A certain genre of apps, especially eg. digital audio workstations, manage to do this and also have a sizeable userbase. Ableton Live is an example here. It see

A certain genre of apps, especially eg. digital audio workstations, manage to do this and also have a sizeable userbase. Ableton Live is an example here. It seems especially sensible if your design does actually have a bunch of controls you need custom rendering for. Honestly, don't let these comments get you down. It's important to act strategically of course, so it doesn't make sense to over-invest in an idea succeeding. But it makes sense to do scoped experiments / proof-of-concepts. I don't think we're "done" with UI framework architecture design, people need to keep trying new things in the space. And I also don't think only Apple (eg. SwiftUI) and Google (eg. Flutter) are allowed to work on these things and we need to accept their gifts from above. Some times, a good quality here is almost not believing that something is too hard to do (while obviously also informing oneself about as much existing work there has been as possible to incorporate it into the experiments).