Nor can it beat the resource efficiency and unified platform look and feel that would be offered if platforms supported some kind of common GUI API... Honestly

Nor can it beat the resource efficiency and unified platform look and feel that would be offered if platforms supported some kind of common GUI API... Honestly I'm not a fan of any of the things you mentioned because they're so fat. They insist on making you build the UI within this humungous runtime that also usually forces you to use specific languages and tooling. These also (with the partial exception of React Native) do all their own rendering, so the user's machine now had to run a million parallel rendering engines. GUI programming in 2020 is a fucking disaster.