It's not just that. There are purposes that
require JPEG and so if I get a WEBP or AVIF or JXL I am actively angry.
I was trying to set the desktop background image on a project laptop last week. I found an image I liked, that would immediately remind me what machine this was when I look at it.
It was an AVIF. Windows 10 won't accept those as desktop backgrounds. It looked, for all intents and purposes, like the search image results were going to give me JPEGs -- the URL ended in .JPG and had "jpeg" as the media type! -- but that is not what I got. This did not work. Refusing to give up, I eventually determined that using curl to retrieve the image gave me a usable JPEG, and so I got my background and now I can tell this stupid project laptop apart.
For my use cases, which is as someone who does light work with images (backgrounds, occasional use in some kind of paint program, occasional insertion into documents or slides), anything that isn't a JPEG or PNG is actively harmful. Not everyone uses images the way I do, but developers need to remember that not everyone is a passive sheep who just stares at things or a power-developer who builds JPEG-XL from source in their sleep. There are people in between, and we don't take kindly to being forgotten.