As someone who lives without constant broadband and as someone who works with people who enjoy accessibility settings in software, I think the current web design trend you describe is disastrous.
It is an awful experience. Mobile data is often sketchy, but these bloated sites don't render a single thing until all the twenty tons of front end crap is downloaded, and all to view a tiny static chunk of text. But hey, they got to use react, a metric shit ton of the latest CSS wankery, and it is connected to every social meejia platform!
