- feature-complete. Once again, there's a reason all UI projects for this "most feature-complete framework" keep reinventing the most primitive controls. Because the web has none, and creating complex controls is a near-impossibility. Also, if it was feature complete, https://open-ui.org/ wouldn't exist.
If you are actually looking for a flexible feature-complete GUI framework, then it's Qt.
These were never meant to build rich UIs. They were meant to build a text page with a few images. That's it.
There's a reason why every single UI framework for these tools re-invents the same primitive controls like avatars and tabs.