[louissan]

well tbh they still do today. Every byte you can take off (very easily at that ...) makes websites: . faster to the user, which does contribute to a general reduced level of stress :-) . use less energy: less bandwidth/less CPU (cisco, nginx, your disk/memory cache.... you name it). Less $$ on your bandwidth/cpu bill @[insert cloud provider here] and less BW/CPU used up on your user's mobile metered connection (because nowadays it's mobile, dontcha know) So even though if many instances over-optimisation is definitely overkill ...in nearly all cases a sane amount of optimisation is good.

my 2p

[handrous]

Sort of. I suspect an under-appreciated part of the modern Web performing so poorly is how casually we throw in vector graphics (SVG, mostly) and draw/transform shit with CSS, these days. Those used to be things one simply did not do without an excellent reason, because they're computationally costly for the client. In maybe a couple years' span they went from "wait, don't do that, it's bad for your user" to "LOL SVG icons are so convenient, let's use them everywhere, and then maybe skew and manipulate them with CSS at runtime because why not".

[EDIT] To clarify, this is relevant to cutting bytes because encoding graphics with SVG or drawing them with CSS can mean shipping fewer bytes than JPGs or whatever.

[zinekeller]

Dither when it makes sense, but using dither in photographic images... defeats the purpose of JPEG and its descendants. Photographic lossy compression is designed to be compressed with non-dithered (as much as possible) images.

[robertlagrant]

They do matter, but not as much as when websites loaded at 0.25kB/s.

[louissan]

yep :)