Design your UX so that any large assets can be requested at will by the user, and indicate the file size? That way it's the user's choice if they want to load that large video over their slow network, etc.
Most users on fast connections are not going to enjoy explicitly clicking to download every background image, font, etc. For videos it might make more sense, but there are many more optional assets to deal with.
> Every time a similar question is posed on HN, someone says "If the assets aren't needed, don't serve them in the first place", but this is i) unrealistic, and ii) ignores the fact that while the typical HN user may like sparsely designed, text-orientated pages with few images, this is not at all true of users in different demographics.
I think your underestimating how perceptibly slow the internet has become for a lot of people. They don't realise they're downloading 2MB of JavaScript, they don't realise what JavaScript or css are. They'll say things like "I think my computers getting old" or "I think I have a virus". More often than not this is just because they're favourite news site has become so slow and they can't articulate it any better than that. All they want to do is read their text oriented news sites with a few images.
