I feel like the market of apps and websites has usually been irrational about bloat because developers tend to have beefy machines. It required a beefy machine just to use Twitter without lag, and now X is the same. In the 2000s it was excessive Flash instead, or Java for apps.
Some sites like Google were able to measure the user-engagement cost of slowness and chose to optimize, but they're exceptional. I doubt most businesses know the cost.
Same for phone. I don't think anyone tests their websites on older devices anymore. Many sites have become useless, because it assumes that you have a massive screen, a modern GPU and plenty of memory. There's no point in having a video as a background, or load an excessive amount of Javascript, just to show me a news feed.
No one cares anymore, and I doubt that any hardware supply bottlenecks will improve that. It's not something that anyone care to measure.