I really, really do not get this obsession with Javascriptless interactivity.

I mean, seriously. Its 2018. JS engines are REALLY fast. And by the way, lets not be deluded into thinking that the Chrome is a lightweight nothing without JS execution. There are already GPU-aided reflow/repaint operations, your whole UI context lives on a different thread, tons of services are pulled back for audio/video capabilities, not to mention addons, HTML engine, etc.

So just learn proper JS, do not overdo it, and write efficient scripts. Its doable.