>>61675875I don't mind Jelly over Alice, but other than that serious reply: too simple designs are easy to forget; Alice still works because of the drill hairs. The overcomplicated designs from, say, recent Nijisanji waves or some you see in the indie sphere is even worse: even not accounting for possible fanworks becoming harder to make as enthusiastic but less skilled individuals will basically give up immediately, details will get fuzzy and different models will blend together. "So this guy has spikes here... three spikes, no wait four, the three spikes were from that other one... I think."
All good designs rather than being simple have very few details and those details are made prominent and especially memorable, so that the character can be recognized immediately.
As some examples, if I tell you: "boy with glasses and a lightning scar", you might think of Harry Potter; if I say: "pink bunny woman", you might reply with Pipkin Pippa; if I say: "guy in an orange jumpsuit with spiky hairs", probably you will say Son Goku. As you can see I only listed two or three details and with only so much it was possible to fully describe a famous character, because rather than having simple or complex designs, they have memorable details.
In conclusion, that's why Asuka is better than Rei.