Take a look at the source for any molasses-slow news site. The only site-specific JS will be jQuery, and a few basic event handlers to do things like show and hide elements, which could have been done with CSS.
99.9% of the JS will be advertising, analytics, and tracking. People understand that these sites are tracking them, but I think most people have not idea just how much tracking is going on. Major news sites have hundreds of tracking libraries loaded per-page. That is the only reason they are slow.
I travel between countries and of course I hate staying in huge cities because they're expensive and noisy. But when you move to smaller towns, there're usually limited options for connecting to the Internet.
Last year in India I spent 2.5 hours incessantly trying to open my bank website to make an urgent payment. All these huge React/Redux bundles were loading for ages, and they aren't cached and there's no support for resuming download after it dies because of some timeout or because you were looking at the spinner for 30 minutes and decided to click reload button.
And even when these huge SPA load, they're totally broken on slow connections. People become lazy and they don't handle timeouts and responses coming in weird order because of the slow channel. Even if you manage to open SPA on slow connection, it's a pain to use, almost impossible with all these XMLHttpRequests on every click transferring megabytes of data after every click or typing any letter. :(
that's peasant level net :P. 100 or bust {literally what I have home and better at work). seriously though, indeed the web is overbloated and I don't think there is coming back
Had Apple not forbidden Flash on iOS, there would be no JavaScript superiority to talk about.
but i wouldn't hold my breath for 1990's style java applet loading throbbers to come back into fashion. there's a reason that stuff got outcompeted by the supposedly "inferior" javascript.
what wasm competes with is flash games, insecure java applets, and npapi and nativeclient in general.