I've done a ton of professional development in Angular, and a fair amount recently in React. I've enjoyed them both a lot.
When I think deeply about it though, I'm not sure that any of it is better than what I experienced on a pretty big GWT project back in 2010. Yes, everyone was horrified that I was compiling Java to JavaScript. But everything just worked. I had a nice MVP architecture set up, and dependency injection using Guice. Maven was a minor pain at times, but mostly just worked to handle dependencies and get things built. Debugging in Eclipse while the app was running in the browser just worked. I really liked UiBinder templates. It definitely didn't feel like heavyweight Java. Just a bunch of lightweight components communicating asynchronously though an event bus.
The JavaScript ecosystem has definitely made some huge strides over the past couple of years. Time will tell if we see enough ROI on the complexity explosion to make it worthwhile.