Every other framework relies on JQuery so--yes, absolutely--it's still a thing.
And if you don't work for a company that is in the JavaScript-framework-of-the-month mode, you should know JQuery is still king.
And if you don't work for a company that is in the JavaScript-framework-of-the-month mode, you should know JQuery is still king.
This just isn't true. OP mentioned React, Vue.js, and Mithril. None of these use jQuery as a dependency. Neither does Angular, Backbone, or Ember.js.
That being said, I don't think knowing jQuery is very valuable for JS developers anymore. Browser standards have come a long way and frameworks are handling your DOM writes for you, so that major use case for jQuery is gone in any website that requires substantial scripting.
But I think that's really only so the Ember jQuery wrapper will work properly. So you're still right.
I'd also argue that this as a current generation framework. I only did a brief skim but the patterns remind me of a Knockout or Enyo codebase with data binding between components doing explicit dom manipulation. The contributors tab shows a 2014 start but I'd have guessed a 2010-2011 start from looking at the code.
I'm an SAP and UI5 developer.
That being said, I agree with your last statement. For better or worse, jQuery still seems to be king.
A better way to state that:
"Is jQuery omnipresent now? Yes.
Will jQuery earn you as much money as on the peak of first gen webapps craze? No, totally no"
I myself was earning CAD $90k just in plain salary at the time when jQuery craze was on its peak and when "a dedicated front-end developer" meant a jQuery developer
Honestly saying, I had no realisation how shitty my code was back then, and now I feel ridiculous when I realise how much a bad dev can earn as long as he does something considered "trendy"