If nobody would care, then how do you explain all the effort that went into MozJPEG, WebP, BPG, FLIF, HEIC, AVIF and JPEG XL?
Do you really think people are working on improved image compression just for fun, and not because "somebody actually cares"?
Also, it is not just about compression, it is also about functionality. HDR displays are a thing, images with alpha transparency are also a thing. There just is no way to properly do HDR and alpha without "dealing with the hassle of using a non-standard image format", unless you think 16-bit PNGs are a good idea for the web.
Sure, if you don't need images, then that's fine and you obviously don't need a new codec. There is a significant chunk of the web though that does make significant use of images.
Do you really think people are working on improved image compression just for fun, and not because "somebody actually cares"?
Also, it is not just about compression, it is also about functionality. HDR displays are a thing, images with alpha transparency are also a thing. There just is no way to properly do HDR and alpha without "dealing with the hassle of using a non-standard image format", unless you think 16-bit PNGs are a good idea for the web.