> Photoshop still can't open webp files,

Why is Adobe so bad at their job? GIMP added webp support about 5 years ago. Paint.NET added it 4 years ago.

> many websites still don't support uploading webp files.

4chan is the only such site I've heard of, and 4chan is notoriously bad at this sort of thing ever since they lost moot. It took them years to permit uploading of vp9/opus webms, for no good reason. 4chan's present administrators are incompetent, but 4chan is barely profitable (if at all) so that's not really unexpected.

But Adobe rakes in huge piles of cash, so what is Adobe's excuse?