A lot of this stuff actually does make the web better. If someone is having trouble loading a site, they can disable features such as custom fonts, images, and scripts. Alternatively, they can just use a text-based browser. I see no need for websites to disable features that most people in developed countries can access just fine from their local café and that anyone else can just disable themselves.

Bloat is something entirely different; I agree that most sites need to cut down on the injected scripts that load more injected scripts ad infinitum. However, it actually takes longer to find a given resource on a different site than to wait for the current site to load. No one’s leaving sites due to loading times unless they’re either really slow or really unimportant.