This seems demonstrably untrue. Basic html development is vastly cheaper than “modern JavaScript” which would give any company w an HTML-only strategy a huge advantage. Why aren’t HTML-only companies dominating in every market?
I think people are complaining about two separate things - actually-static-ish websites like newspapers, shipping 10MB, and web apps like Facebook shipping 10MB. The latter is an unavoidable outcome of shipping Serious Software; the former is mostly driven by ad networks, not development ease.