>>58222060 (OP)
Gen 3 is in an awkward aspect ratio with weird washed-out colors and squished sprites. That said, gen 1's sprites are utter dogshit, they're off-model trash, especially back sprites, gen 2 is... fine, but still rough, and really sprites didn't fully come into their own until Gen 4 when the techology caught up, then sort of peaked with gen 5 with full animation and stuff like eyes closing when a pokemon goes to sleep.
Gen 3's sprites, like almost all of its features, is the "awkward puberty" of the franchise. It changed a ton of things from gens 1 and 2, but not enough to be a fully step like gen 4 was. It added abilities and natures and IV/EVs and a primitive version of the physical/special split, but all of those things were improved upon in gens 4 and 5 (Hidden abilities in 5, the true physical/special split in 4) and even in later gens (i.e., nature mints in latterday gens, super training in Gen 6).