HEIC is this plus a kitchen sink of features for digital camera rolls, which aren't useful on the web, all wrapped in a ton of legacy ISO BMFF complexity reaching as far as Classic Mac Quicktime. BPG structure is much more minimal and pragmatic.

However, BPG is unnecessary nowadays. Modern browsers support AVIF, which is HEIF+AV1, so basically HEIC with the painfully patented bit swapped for a freely licensed one.

Really hopeful for AVIF but you can't use it on iOS https://caniuse.com/?search=avif :(

It seems that way - I read this [1] which does a high level comparison of the technologies. It does seem like BPG is patent encumbered by the underlying H265 algorithms (aka HEVC) [2]

[1] https://www.zyxtech.org/2019/06/13/what-is-heic-heif-plus-a-...

[2] https://en.wikipedia.org/wiki/High_Efficiency_Video_Coding

It looks like BGP actually predates HEIC. HEIC technical document finalise in 2015. The GitHub mirror of BGP has history back to 2014.

I'm not saying which one is earlier as I have no idea, but comparing these two dates doesn't seem to be a good way.

Implementation of HEIC existed before its documentation finalized.