Yes, but if they did their own language it would have almost certainly died in obscurity.

React won because it solved a real pain point for a group of people, using the techniques they were already using... but better!

Having built large apps in angular, handlebars, and jquery... it was (and still is) a godsend for building highly interactive, stateful web applications.

I am deeply skeptical of some of the stuff that people are doing now wrt. putting backend logic into React components, but the fundamentals of React are still very reasonable to me.