Well if you focus on components only in your app then sure, not much needed. But complex apps need much more, like testing infrastructure, routing, data layer, service layer, tons of utility functions (last time I toyed with React it did not even have debounce ... Library for UI w/o it seems weird for me) and likely something else.
But hey, most apps are simple, so no need for all the above. I would say Ng/Ember are more specialized / niche.
But hey, most apps are simple, so no need for all the above. I would say Ng/Ember are more specialized / niche.