Let's take it further: That atmosphere of wastefulness not only concerns bandwidth and energy use but also architectural decisions. There's technology that punches far above its weight class in terms of efficiency and there's the opposite. It seems like a collective form of learned helplessness, on both sides, the vendors and users. IMHO, the only real reason for slow, JavaScript-heavy sites is surveillance and detailed, distributed profiling of users. The other would be animated UI giving dopamine hits, but that could totally be confined to entertainment and shouldn't be a cue for "quality" software.