[jillesvangurp]

The reason we have jpeg is because png is not good enough for photos and people prefer the lossy compression of jpeg over using png. The reason other lossy formats are struggling is because they are still lossy. This promises to basically be good enough for just about anything. That sounds like a big promise but if true, there's very little stopping major browser implementing support for this. I'd say progressive decompression sounds like a nice feature to have for photo websites.

Compression is still majorly important on mobile. Mobile coverage is mostly not great except maybe in bigger cities where you get to share the coverage with millions of others. Also mobile providers still throttle connections, bill per GB, etc. So, it matters. E.g. Instagram adopting this could be a big deal. All the major companies are looking to cut bandwidth cost. That's also what's driving progress for video codecs. With 4K and 8K screens becoming more common, jpeg is maybe not good enough anymore.

[GoblinSlayer]

File size matters for networks, not compression. Compressors have an interface where you specify desired file size and the program tries to produce a file of that size. With better compression algorithm the image will be just of a better quality, time to download and cost per GB will be the same.

[spider-mario]

> Compressors have an interface where you specify desired file size and the program tries to produce a file of that size.

That’s not really the case for JPEG XL, where the main parameter of the reference encoder is in fact a target quality. There is a setting to target a certain file size, but it just runs a search on the quality setting to use.

[jillesvangurp]

This algorithm is supposedly lossless and requires no fiddling with such settings. So a good enough non lossy algorithm could be quite disruptive. Of course with a lossy algorithm, if you throw enough detail away it's going to be smaller.