The amount of diversity in JavaScript frameworks is NOT good in my opinion (a back end dev who needs to get a bit of front end stuff done every so often).
Just use React as the other two are copying/converging toward React.
All the other web app UI frameworks? Noise, they won't amount to much and add very little. The last release worth paying attention to was React 2 years ago. Hardly a breakneck pace.
(Though having tested React recently, its the best of the ones I have used).