There are very interesting values here.

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.

We had plug-ins to support them all.

Interesting.

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.