I feel the exact same way, and it seems a bunch of other people do as well.

The other day I downvoted a post purely because of this issue, but yesterday I decided to reach out to the OP instead.

I imagine the latter is more effective not only to encourage OPs to not use .avif (assuming that’s even the issue), but because it might get noticed by someone who actually understands and can fix the issue on Piefed/Lemmy if it’s fixable.

I’m usually big on proper bug reporting, but I literally don’t know where the issue stems from and I don’t currently have the time to DM a dozen teams/people asking if they think it’s their code that’s causing it, as I’ve learned is the proper method on the fediverse when I’ve tried to “modmail” like I’ve done on Reddit in the past.