Memes

It's good for serving 1st-gen ephemeral images that you don't care about, but bad if you want to keep an image around for archiving or sharing. It has many random limitations with its lossy and lossless format, including a low bit depth, no support for 4:4:4, no support for HDR, and no support for progressive decoding. This is especially annoying for a lossless format, as you'll often be losing data when converting from a format like PNG, defeating the purpose of lossless.

You might be surprised how good JPEG still is in this day and age. We have dragged JPEGs corpse across the decades with newer and better encoders, and JPEG is actually still a solid format because of this effort. People have a deep impression that JPEG sucks, because it used to suck. The JPEG we know today is not the JPEG of the past. MozJPEG is an excellent modern encoder and gives great results at very fast encode/decode speeds.

People might want to argue about how good WebP is in comparison to JPEG, but in reality there are two newer formats that far outclass WebP and don't have its quirks - JPEG XL and AVIF. JPEG XL is the best option we have currently and it's not even close, given that it's a real modern image format and not just a video codec repurposed for images, like AVIF. The problem is that Google is putting its weight behind AVIF, and is trying to kill JPEG XL by taking support for JPEG XL out of Google Chrome. Firefox has followed suit as they're also a member of the AOM which developed AVIF. Almost any fork of Google Chrome or Firefox puts JPEG XL back in, at least.

This article goes over some of the competing formats, and I especially like this image as a comparison matrix. You can probably find more articles by Cloudinary and Jon Sneyers on the topic. It's one of the most obvious instances of why we should not be letting Google rule 100% of the browser market - they can kill competition on things like this with the flip of a switch.