This is all high-effort and I am impressed, thank you for making it!
And yeah, I think it's natural that setting that hit so hard when they first appeared are well-remembered. I was thinking they "lived fast, died young and left a pretty corpse", but that's not actually really true*, so it's got to be the initial impact, and their uniqueness. Planescape is obviously the most disproportionate but Birthright isn't far off given how extremely brief and specific it was.
* = In particular, Dark Sun got the 2nd box set which had no art by Brom (or even Baxa, who style I hated but got the aesthetic really well), and which just generally trashed up the setting by, IIRC canonising the Prism Pentad (which is one of the worst bits of D&D fiction ever, and that's saying something - it's so bad that we knew it was bad, and were mid-teens with very very low standards), and adding in all sorts of more generic junk (including some seriously green areas which weren't "basically myth"). And the 4E version of DS was only okay. Planescape got Monte Cook's special "let's ruin this setting before I leave" adventure, I'd say it was the adventure-writing equivalent of trashing a hotel room, but it's almost the opposite, it's more like if you changed history so Nirvana (or whoever, Pink Floyd if you want) didn't break up, but just decided to do godawful Middle-of-the-Road pop-rock instead, but luckily few people read it (though the 4E DMG2 did follow it, for which I will forever curse whoever wrote that bit of the DMG2, you had a chance to save Sigil you jerk! You've failed this city!).