I distinctly remember when Reddit rolled out the new "mobile site" because it took multiple seconds longer to load than the previous one and now crashes my IPad 1 and is janky on my IPad 2-ish quality Galaxy Tab.
If these companies want to do something for the environment and their customers, they should make their sites blazingly fast through simplicity not lazily loaded this and that progressive client side whoochathings.
Ironic.
But why can't I find this blog post? I just spent much longer than I ought to have searching for it and can't find a trace of it. You have to wade through a lot of SEO stuff that comes up with the search results, but restricting to older content helps (I think this happened at latest 2010 probably several years before that). The old google blog I think was google.blogspot.com or googleblog.blogspot.com but you need to search it on the wayback machine and I can't see a way to do that except by hand.
The Web needs an anti-bloat movement where animation is minimized and documents are mostly server-rendered.
Instead please extend HTML with useful entries and stop using Javascript for layout and handling connections and refreshes.
What you said suggest the use of migrated like Google AMP. Server side had no idea how things are supposed to be rendered. Trying to force it via JS is an extra crock.
Server side has an idea on how things are supposed to be rendered for content-based documents.
Games and complex apps need JS, but readable documents don't. Not everything should be "an app".
Animation is often not accessible and it's a problem that needs to be fixed.