The relentless barrage of new frameworks makes many people stressed thinking they need to learn every last one of them; or they're just tired of the churn and would rather things were a little more stable in the industry. The rapid move from one thing to the next can prevent people going deep into anything, so they attain low-level competence many times over without gaining deeper mastery of anything.
I have heard stories from some places that have moved from Backbone, to Angular 1, to React or Angular 2+, to Vue... all in a few years. Even when they were separate projects that is quite a lot of training/upskill overhead just to keep producing similar output (as in, they all produce javascript-based applications).