Progressive photos always irritate me. The photo comes on my screen all blurry and out of focus and I'm disappointed that the moment I thought I had captured didn't turn out. Then, 3 seconds later, the picture changes and gets slightly better. Then I'm hopeful, but disappointed again. Then i think, "maybe it's not loaded yet", so i wait and hope. Then 2 seconds later it changes again. Is it done? Is it loaded now? Will it get better? Is my computer just dog slow? How long should I wait before I assume it's as good as it's going to get?
I know it's a small thing and doesn't really matter, but I don't like progressive photos.
Edit: This is just one context. There are plenty of other contexts where progressive is very useful.
On the other hand, it also doesn't constantly change the DOM, moving you across the page because images above what you're reading are getting swapped in and now you're looking at the paragraph above the one you were reading.
The progressive mode in Jpeg and JPEG XL is quite different, because the quality is so much better your perception of it changes. Where Progressive Jpeg are literally useless before it finish loading, JPEG XL provides decent quality.
I know it's a small thing and doesn't really matter, but I don't like progressive photos.
Edit: This is just one context. There are plenty of other contexts where progressive is very useful.