>>121125I don't speak for everyone, but Rebecca is a fun character who embodies the chaotic nature of Cyberpunk, both as a genre and as a franchise.
Lucy is great too, don't get me wrong, but put a gun to my head and I will pick the chaotic loli over the sad netrunner any fucking day.
As far as who has the "better design", it really just comes what you like in an aesthetic sense.
Lucy's design is reminiscent of Motoko Kusanagi's in the original GITS or SAC, which is great and all, but I don't need dollar store Kusanagi.
Rebecca's design, on the other hand, especially with the overall color scheme(gotta love them pastels, my mans), really makes her memorable. The eyes, the tattoos, the weird skin color she has, it all adds to an overall package that is more interesting.
Also, more people than you would like to admit like lolis. That probably has a lot to do with it lmao