I feel like Neeko should have been melee so her camouflage is needed

From watching gameplay I see a champion with a strong camouflage passive that she doesn't need to use at all to be relevant. She has a very strong long range and easy to land root/poke, a medium range aoe poke and a large aoe nuke that she can very easily setup with her root.

The camouflage is just tacked on instead of a core mechanic that enables the rest of her kit.

In comparison look at reworked Eve. She has permanent stealth after 6 but she's melee with only one medium-ranged ability and has a charm with a 1.5s setup time. If she wasn't stealth it would be very hard for her to ever get a charm or an ultimate.

Neeko looks cool and I like the idea of a mimicking champion but why is her kit just as effective if she's fooling enemies or not?

Such a cool passive like that deserves to be in a kit that NEEDS it.