Exotic file formats, like exotic JavaScript language constructs, tend to perform poorly because they are not optimisation targets. And they are not optimisation

Exotic file formats, like exotic JavaScript language constructs, tend to perform poorly because they are not optimisation targets. And they are not optimisation targets because - obviously - no-one uses them. To my knowledge there is no particular intrinsic reason that JPEG-XR decoding cannot be moved off-thread. The solution to this problem is to start using these new technologies, so the browser vendors can prioritise work to make them performant. It is not to write articles that entrench that neglect and tie us to flawed, ancient technologies from the 1990s. It gets worse. If there's one kind of meme that survives a long time in the development world, it's performance memes. Rumours about poor perf invariably end up haunting technologies with FUD long after any issues have ceased to be relevant.