There are a couple I have in mind. Like many techies, I am a huge fan of RSS for content distribution and XMPP for federated communication.
The really niche one I like is S-expressions as a data format and configuration in place of json, yaml, toml, etc.
I am a big fan of Plaintext formats, although I wish markdown had a few more features like tables.
Chromium had it behind a flag for a while, but if there were security or serious enough performance concerns then it would make sense to remove it and wait for the jpeg-xl encoder/decoder situation to change.
It baffles me that someone large enough hasn’t gone out of their way to make a decoder for chromium.
The video streaming services have done a lot of work to switch users to better formats to reduce their own costs.
If a CDN doesn’t add it to chromium within the next 3 years, I’ll be seriously questioning their judgement.