[tlamponi]

> I dont want 15KB, because difference between 15 and 70 is 5 milliseconds.

And I want it, as on travelling or mobile I'm golden if I get 1 MBit/s (= 128 KiB/s) download bandwidth, more often it's around 300-400 KBit/s (37-50 KiB/s), so:

  1 MBit/s and one image -> 546 ms vs. 117 ms
  300 KBit/s and 1 image -> 1892 ms vs. 405 ms

Most sites have more than one image, say five for some realistic example:

  1 MBit/s BW:
  AVIF 15 KiB: 0.6s
  JPEG 70 KiB: 2.7s

  300 KBit/s BW:
  AVIF 15 KiB: 2.0s
  JPEG 70 KiB: 9.5s

That's both quite the noticeable difference.

In my residence I'm lucky and get 100+ Mbit/s and even 1 GBit/s at work, but there are lots of countries in the world that don't and once one is affected by that, like I on my train travels, it gets really noticeable which sites have low-bandwidth ignorant engineers, causing not only frustration but often actually impacting life in more meaningful ways negatively.