I always thought `diversity is good`, but maybe in certain instances it's not. Perhaps a certain saturation level is reached and diversity just adds noise to the system and causes enormous overlap and your "smart person energy" is mostly spent re-inventing the wheel
Honestly, after React, Vue, Angular, Ember, Stimulus, Meteor and Backbone, how does anyone truly have time to learn learn about Svelte, Marko, Knockout, Aurelia, Riot, Omi, Foundation, Catberry, Composer, Yo-Yo, Vomit, Mithril, Polymer, Sencha... I'm not making a single one of these up. I know that I'm forgetting at least a half-dozen.
Note: try Stimulus!
Seriously though, if you're following every development on more than two JS frameworks, you are procrastinating, lying to yourself and not achieving your full human potential.
Many people thrive in these kind of frenetic, fast changing environments. Others (myself included) don't.
All I know is that after I help my friend with her React stuff, I go back to Rails and thank my lucky stars.