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.
QOI is just a format that’s easy for a programmer to get their head around.
It’s not designed for everyday use and hardware optimization like jpeg-xl is.
You’re most likely to see QOI in homebrewed game engines.