>>49127485I think what helps Gen II is that it's one of the more consistent series of Dex Sprites, Gen I just has a lot of jank in its sprites due to being the first, I mean you get a lot of sprites which are just a mess more than anything. Gen III is weird cause in RS they looked like they were going for a different artstyle for the sprites which you could see pretty well in Pokemon like Nosepass and Claydol, and some of the Pokemon not in RS got some questionable sprites as a result although FRLG did help to fix that up somewhat you're still left with a number of Johto Pokemon whose Gen III sprites just look off.
Gen IV has this issue where any Pokemon that wasn't in a regional dex has a Gen III looking sprite while the ones in the regional dexes look fine, this is really obvious between Pokemon that weren't in DPPt but were in HGSS cause their DPPt sprites look jank as fuck while their HGSS ones actually look pretty decent, which mainly means Hoenn Pokemon got screwed over cause most of them got stuck with one shit sprite for the whole generation.
Gen V I think is the only generation whose spritework is on par with Gen II but most Pokemon only got one sprite in the generation compared to Gen II's three sprites with only minor alterations between BW and B2W2 (except for Cottonee fsr), of course Gen V also has the rigging animations which is a whole other can of worms but in terms of the still sprites I think Gen V probably comes the closest to matching Gen II since there's just a consistency to every Pokemon's sprites in those generations.
