Some like Release 1.8 have the Ocean Monument or armour stands and tweaks that may be appealing, others like 1.2 or 1.3 had Jungles/Villager trading, the Desert Temple, the old creative mode/new creative mode with tabs for example.
Some features can really change the game for whether certain blocks sure, but also the way the game feels like swimming, sprinting, how much the game uses of RAM, animations, mob AI, stuff like that.
It's why I think quality of life updates can be important and think 1.15 wasn't a bad update, sure it had bees but I cared for the tweaks more than I did just bees.
If fine with mods have mods that add features that come close to them (blocks, ones that remove hunger, stuff like that).
Some old versions like when I play 1.2.5 feel old enough of mob AI to be old school, hunger is slower to deplete (as far as I remember), animations are different too.
I kind of go for a 1.13+ if I care about swimming, 1.2.5 for an old enough feel but don't want to go too far back into Beta versions and anything in-between it really depends.
Mods usually determine what I want as I usually only care about Redstone blocks or hoppers for 1.5+ Release versions usually as I like to have them. Mods with the feel of the older versions does enough to convince me to play that far back.