JavaScript doesn’t run on a Commodore 64 either, but that doesn’t mean we shouldn’t use it.
I’ll still argue that an efficient web app will be a significantly better experience than waiting for pages to load, even on a 10 year old tablet.
And to support that, I do most of my mobile testing on my old iPhone 6—which is, coincidentally, 10 years old. I don’t have trouble with JavaScript on that.
I think what it comes down to is there are a lot of unskilled developers out there that misuse JavaScript… and PHP.