Front end browser development is littered with dozens of front end frame works that have fizzled over the years. YUI, Prototype, script. aculo.us, etc. All popular in their day. jQuery is still active but certainly on the decline.
You want to be a good front end developer? Learn about the DOM model. Learn about HTTP, HTTP/2 and CSS. Learn the fundamentals of how all that stuff works together and then you'll never need to worry about picking up whatever front end framework is used by the cool kids.