Plus, Angular comes with a bunch of tools in itself. If you take a break for a while you'll have to re-learn the new ways of doing things a few versions later. This is not only taxing, but makes one reluctant whether to invest the time in it or not, and the learning process is a bit encumbered by the idea that it all may go to waste soon-ish. The reality was that even older tools proved to be useful to me as I had to pick up and maintain older projects and having learned that it made it easier. But this may vary from case to case.
Moreover, when something new comes out, everybody is hyping it and when we start using it in my work place, my gut feeling tells me to wait for v2 or v3 or so, such that I don't have to deal with the many confusing changes that take place in the few iterations. But I do that just because I had some bad experience in the past. Others break their teeth with the same frustration that I had. They too may build their reluctance as I did.
For example I worked on an Angular project and invested a bit of time to learn the framework and certain libraries. I completed the project and it was successful, but my new projects aren’t to be done in angular anymore and I can’t apply all this knowledge, at least for the time being. Am I glad I learned this? Sure. But, this theme has repeated so much in my career that I am reluctant to jump onto a new thing. Instead I doubled down on F# and started learning scheme.