I guess, ESR misses the “ever” part in the parent comment. Once you update from Firefox 78 ESR to, say, Firefox 91 ESR, you get all the newest UI changes and a

I guess, ESR misses the “ever” part in the parent comment. Once you update from Firefox 78 ESR to, say, Firefox 91 ESR, you get all the newest UI changes and all. There is a certain demand for “the boring UI”. Using as much of the native controls as possible in the browser UI, not moving things, not inventing new behaviour, and so on.