I know people love to shit on JS for being blisteringly fast, but does it really apply here?

All 3 of "the big 3" are over 4 years old, making all of them older than windows 10...

And of the notable category:

Aurelia: around 2014

Elm: around 2013

Inferno: around 2015

Polymer: 2014

Preact: 2016

ReasonML: 2016

Svelte: late 2016

So most a few years old. Yes, it's faster than older technology stacks, because the web is still evolving quite quickly, but it's not as blisteringly fast as many make it out to be.