This reads more as an argument against dithering. Sure, it saves bandwidth, but all the images in the post look awful. If I saw pictures like these on a professional website, I’d assume the people behind it were incompetent.
If you really want to save bandwidth, you’d be better off looking at better formats like AVIF, and WebP.
Those will shave off a lot of extra bits, especially AVIF, although that is not universally supported yet.
Combine that with making a the images a little smaller would save you a lot of bandwidth, without making your pictures look like they are 20 years old.
Whenever I look into the modern formats excited to save 50% on bandwidth, I realize I'd have to spend 50% more on storage since I still need my fallback to JPEG. WebP is probably the best supported but isn't available on slightly older Macs or iOS devices. There are tons of iOS 12 iPads and pre-Big Sur macs in service.
given the cost difference between storage and bandwidth, that's probably a worthwhile tradeoff. Especially given the common usecase of store once, send many times.
If you really want to save bandwidth, you’d be better off looking at better formats like AVIF, and WebP.
Those will shave off a lot of extra bits, especially AVIF, although that is not universally supported yet.
Combine that with making a the images a little smaller would save you a lot of bandwidth, without making your pictures look like they are 20 years old.