Smaller files can be inlined it into the markup or other containers. If you can get it down to 1.5KB, it can fit in one ethernet frame.

I'd be quite surprised if frontend developers know the size of an Ethernet frame or TCP ICW. I'm all for these kind of optimizations, don't get me wrong, but I just don't realistically see them mattering any more.

I see this as largely a tooling problem.

Fireworks from the early 2000s did a great job helping with optimizing images. These days no one even thinks about it. Tools like Sketch will export SVGs but embed base64 encoded data URLs of 600dpi PNGs in them. Unobservant devs don't realize this is happening which lead to SVGs that are tens of megabytes. Sketch should know better than to do something so ridiculous without any sort of indication or warning. It's shocking how few professional design tools have working or optimal image optimization. I can drop PNGs from any app into free tools that shrink them down losslessly by 50%.

Flash did binary vector art in late 90s and we still haven't caught up to that in 2021. SVGs are still much larger than their SWF counterpart, and only in very few circumstances is any of SVGs functionality superiority relevant.

There's a big void around non-technical designers and untrained, unskilled FE devs that don't know about these problems or solutions. Is the solution yet-another binary vector format that is dead-on-arrival from google? No. But I like that there's some attention to this problem.

The large services with user content care a lot. If you are Reddit instead of Facebook performance starts to matter.

Reddit is actually a great example of not caring about performance. See those tiny reward icons rendered at 12px? Here's the source image, a 512x512 1.6 MB APNG: https://www.redditstatic.com/gold/awards/icon/Illuminati_512...

Yes but icons tend to be downloaded in groups so you can x10 that value. At 160 KB it starts to look like a prime target for optimization.