I would have loved to have seem some photos of this industry out of Africa though.
Like the pass extraction of PNG [0] would make it somewhat possible, but you'd need to be dropping packets which you might as well receive. I don't think you'd be able to break after the first pass.
JPEG is probably worse.
However, the super-modern formats that are still gaining popularity, like WebP absolutely do support this. At the core of WebP is block prediction, so a low-bandwidth application might actually assume the values of certain blocks so it doesn't need to fetch them.
[0] https://www.w3.org/TR/2003/REC-PNG-20031110/#4Concepts.Encod...
https://support.google.com/chrome/answer/2392284?co=GENIE.Pl...
https://www.thewebmaster.com/dev/2016/feb/10/how-progressive...
Besides, there are areas in Germany today where you can't get >1Mbit connections.
As to why the images are so huge, well, nobody gives two shits about download size any more in a world where you’re also probably pulling down multiple megabytes of ad images and JavaScript because every damn webpage has to be an app even if it’s purely static content nowadays.
[1]: https://www.crunchbase.com/search/funding_rounds/field/organ...
That said, running these images through any basic image compression utility will probably cut down the size by 50-70%
In some sites/blogs it's good to put many pictures. It really depends on your readers.
In HN people look more for content based articles and they don't care if an article is mostly text without pictures