I like the use of a virtual DOM and the custom tags. Custom tags is what makes Angular easy to use. But I would like to see some benchmarks. I'm afraid parsing every single byte of every single html template is slow.
Riot also needs widgets. Lots of lots of widgets for material design widgets for making desktop and mobile apps, and twitter bootstrap like widgets. Good developers are lazy developers. They don't want to make an entire eco system.
In theory Riot is super fast. The DOM is parsed once when a tag is initialized and after that the text nodes and attributes are only updated if the expression results to a different value. The expressions are compiled and cached.
Beware the way you're benchmarking, e.g. immutable structures and pure (& immutable-state-aware) components can make a pretty huge difference in react.
Riot also needs widgets. Lots of lots of widgets for material design widgets for making desktop and mobile apps, and twitter bootstrap like widgets. Good developers are lazy developers. They don't want to make an entire eco system.