My problem with VanillaJS is that browser companies ship browsers with VanillaJS support already. This is a clear case of picking winners, regardless of VanillaJS's excellent benchmarks. Why should all these browsers ship with Vanilla? Why not Vue? Why not MooTools? Why not Moo.fx?
Not sure Vue falls in the same category, Vanilla lists "features" such as: "DOM (Traversal / Selectors), Prototype-based Object System, AJAX, Animations, Event System, Regular Expressions, Functions as first-class objects, Closures, Math Library, Array Library, String Library". Not "component-markup-to-JS transpilation" or SPA v-dom render loop
Like you said, VanillaJS isn't inherently faster than any of these frameworks, but the cost to the user (and the increased API surface) isn't worth that tiny improvement in code clarity.
I did not say that. VanillaJS is pretty much faster than all of those other frameworks. Can you point me to a library that has better benchmarks than VanillaJS?