I do find it slightly strange that saving a few bytes from the size of an image is suddenly of such pressing importance that we need to resort to all these hacks.

JPEG2000 has been available in some browsers for years and years now, but I've yet to see any site selectively sending it to supporting browsers to save bandwidth, or anybody advocating for doing that. JPEG2000 first became available in browsers 10+ years ago when connection speeds were very much slower than today, so the benefit of using it was even greater back then, yet it saw very limited adoption.

Also I note that the saving from using webp compared to the optimised jpeg is only 18kb, meanwhile the page wastes 40kb of bandwidth on a Google analytics script. What Google gives with one hand it takes away with the other.