XII is the sleekest and most immediately comprehensible so I think it's that
I know it originated the trope, but I think the original VII menu has been tarnished by all the bad RPG Maker games that use the exact same menu format, it makes it feel kind of low rent looking at it now, if you don't have nostalgia for it. I'm kind of surprised seeing people say VII's is the best, but I wonder if nostalgia and being in the right time/place when that game came out has something to do with it.
And that FFX menu's just awful, just feels like big overwhelming block of text without images or enough space to let anything breathe. It feels like it'd take just a bit too long to get to what I need while navigating that menu. FF1-6 menus feel a bit more simplified which I appreciate. There's a lot of information there still, but it feel manageable and well-spaced.
Note that I haven't played FFVII or FFX myself, but have absorbed a lot from those games just from cultural osmosis.