This is not pointless, but it is pretty uncontrolled. Basically, there is a natural tendency for engineers to want and rewrite old stuff, once all the flaws of once-cherished yesteryear solutions are glaring. Normally, engineers don't have a freehand in ditching old projects and rewriting from scratch, so they have to maintain what exists.
But with all the startups and the site redesigns, now they can, and they do. Why not--it's fun, it replaces old solutions that showed their limits, and the scope is somewhat limited; it's just a website, after all. Moreover, everyone can jump in and create their foobar.js lib or framework; the core node/JS is pretty easy.
> It really feels to me, at least, that there is a direction that the tooling is heading.
It is quite uncertain. Progress is made when you build on previous work, but here it is mosly about saying that the old solution doesn't work eventually, so let's do it this way instead. It looks a lot like infinite recursion, with pretty thin state.