Right so now we need a workflow to do something as simple as looking back a few pages. I know it’s necessary but it’s definitely a regression.
I know this works because I've seen it with some PDF readers on desktop in the past, when I lucked into a combination of lightweight document and right "fit page to display" scaling. And, of course, this works natively in browsers with PgUp/PgDown, but only on the few remaining websites that haven't been thoroughly shittified (no "en-" there on purpose) with JavaScript and excessive styling.