forced to be a thing by google
bad-ish support in some applications or places even to this day
always used to further reduce filesizes which means you are most of the time transcoding lossy jpgs and making them more lossy (lemmy is specially into this), which means that the alleged better quality is actually useless

jxl would make a better replacement for this last thing since you can losslessly transcody jpgs with ~20% filesize and in my testing, pngs with ~50% (though jxl lossless decoding is cpu heavy right now), lossless transcoding also means you could keep jxls in server, then give it to the client if it supports jxl, or transcode back to jpg if they don't (this saves bandwidth and storage at the cost of some cpu usage, but jpg transcoding is really fast and you can cache highly used images)