I have long complained that Gmail seems to want me to be inefficient. E.g. instead of giving me a scrollable list of, say, 500 emails in response to a search, they insist on showing me screenfulls at a time. Plus, they don't easily adjust to my current screen size - they always give me circa 20 items at a time. Even when I am on large screen that can support 120 such.
Now, there may settings, like showing 100 conversations per page. But (1) those don't apply to everything, e.g. not the searches - and if there is a setting that does, I have not found it. (2) They have not provided easy to adjust controls, such as dragging to enlarge the numbers shown.
I used to imagine that this was due to web HTML / Javascript limitations.
But now I suspect another reason: if they help me be more efficient, I look at fewer ads.