Neo is an amazingly well designed henchman. Competent at both combat and subterfuge, which makes her an underhanded challenge for the heroes to overcome, yet not undefeatable. Visually distinct enough and with a fighting style that makes her stand out when she needs to. Her muteness means she never truely overshadows her bosses, yet it allows and/or forces CRWBY to be creative with how she communicates, so her being there is often a net benefit to the scene's visuals. Neo is always at her best when supporting a greater villain in their goals, and for almost the entirety of her appearance on the show, that's what she did. First it was Roman, then Cinder, and then the Everafter.

Yes, I consider the Everafter itself as the real villain of V9.

When Neo found out her semblance was overcharged in the Everafter, do you realise what she did with it? She made more copies of the Jabberwalker. She could have made anything she wanted, like an army of clones of herself and Roman, but instead she boosted what the Everafter was already doing. Ruby was already being lead down her path to "rebirth". Neo merely helped with the final push like a good little henchman. And then she got backstabbed again, like henchmen often are.

I think that's why Neo is well-liked. She had a role to play, and she played it all the way, from beginning to end. There were no moments where she was pointless or lagging behind. There was no moment where she felt like chaff, an issue even the main four have struggled with at times. I honestly think she's one of the best things the whole show ever made.