It's useful for most of the reasons listed in the parent article.
You can also do quite a lot in CSS these days for interactivity - and with better performance than JS. Expand/collapse sections (with animation), menus including transition delay for more mouse forgiveness, slide out panels.. Also pretty easy to then tweak it for alternate mobile layout.
I am a fan of the HTML5 validation though - offered feedback when they were working on it that I think made it into the spec like interaction of required and hidden elements...
And, I suspect for most of our forms the simple patterns of HTML5 validation would be fine, it's just that sometimes it wasn't, and it was easier to be consistent in how validation worked and looked... So. Chalk it up to laziness. So long as the forms still worked we decided to let it be.
It's not 2015 or 2016 anymore, not even close. We're the better part of a decade moved on. This is not a valid argument any longer. JavaScript is a critical part of the modern web experience. You may not like it, but that doesn't change the fact.
This is why things being generally available that have the potential to be harmful causes such a debate, because on the one hand it’s useful, on the other it’s harmful.
The reason people blame the tool is because the tool enabled people to be able to maximise their harm, and people will maximise harm when given the opportunity.
In this case: JavaScript enables people to externalise their processing cost into people’s own computers, which is a huge potential for harm as it’s a really asymmetric power dynamic.
Nothing has changed.
Source: personal experience, as one who blocks JavaScript by default because it makes the web better more than it breaks things. Also very occasional observation of people browsing the web with very similarly-configured browsers apart from the disabling of JavaScript, and of people browsing the web without even uBlock Origin or similar (and that’s really painful to watch).
Basically, I'm willing to trust a site that I've deliberately visited; but if they want to load a score of scripts from sites I haven't deliberately visited, and I can't see content without them, I'm outa there. Often these are big scripts; and the site-owner can't possibly be vouching for them, if he's not even serving them himself.
I think linking out to 3rd-party Javascript is lazy and irresponsible. Any testing you've done on it could become obsolete at any time, without notice. It's done to avoid having to keep up with patches; "No, I don't know what version of JQuery you got served; you were supposed to get served the latest".