And how many pages do the outerplanes other than the Outlands get in the 2e set compared to the 0 in the 5e set? And of course the Outlands gets more than 4 pages in the 2e set, outside of the gate towns. And more factions are detailed in the 2e set. And the 2e set gives setting advice on building planescape adventures, which the 5e setting doesn't do. And the 2e set places more gods onto various specific planes as home than the 5 setting does. And...
But hey, you get a couple more pages on Sigil in the 5e setting!!