"Nothing against JS, but it has better things to do than setup and manage your accordions or offscreen navigation menus... "

Perhaps this is referring to "things" such as data collection, surveillance and ad services

It would be interesting to see how Big Tech and other adtech companies would accomplish the same level of data collection, surveillance and ad services without the use of Javascript

As for "nothing against JS", I think some web users (cf. "developers") who dislike adtech and the ad-laden web they perpetuate might have something against it