Somebody could think of the web as primarily a platform for consumption, in which case it is OK for it to support a limited number of formats, actually desirable because it reduces the attack area.
Another is that the web is connected to general purpose computing in which that case the web browser competes with GUI shells (e.g. explorer, finder) and should be able to support every image format that is commonly used on the platform.
Back in the 1990s most platform supported a lot of file formats that weren't JPEG or GIF but browsers didn't support them and only a small set of formats have been added since then.
A long time ago I ran some sites that hosted large image collections and I struggled with costs so I did a lot of thinking about how to optimize storage and transfer. I came to the conclusion about 5 years ago that WebP is consistently a win over Jpeg, but I've never been a fan of AVIF. Yeah, it does great for big blog hero images that people don't look at closely, but it makes my mirrorless shots look like they were shot on a cheap Android. Yeah, I've seen that picture of the F1 car and it is superficially impressive but if you look closely at the highlights you can see that it erased the real highlights and replaced them with something plausible but... different.
I'm on the other side, I hate webp because if I download such an image a lot of apps don't support it. So typically I need to screenshot it instead to get a usable jpg/png.
Now one more format to hate.
I would say webp/jxl/avif is anti-general compute, since they require very recent software.
I know that end-users making memes or whatever aren't a demographic that will matter for adoption, but it seems really weird that this is still a problem on Windows and Mac in 2026. I've searched for browser extensions to no avail.
I just tried it out now, using Waterfox on macOS 27. The save image dialog literally already has a Format dropdown. But I'm guessing it's just a weird part of some native dialog, it lets me select between "WebP Image" and "All Files". This kind of design could've been used to allow the user to save it as a different format than what it was served as.
If you have support for multiple file types, you're already using multiple libraries or you're using a library that handles several kinds of file, either way you can and should update that.
Imagine if installing libzstd meant that every program on your computer suddenly knew how to use ZSTD compression, or adding libjpegxl added support to every browser, word processor, and age editor you’d already installed.
Some parts of AmigaOS were wonky, like lack of memory protection. Others would still be phenomenally useful today.