There are good Non-GW 3D designs, but not that many.
I agree they generally aren’t as good as GW, but that’s because they are made by 1 or 2 artist and not teams of people doing concept and creation work, like GW has.
Also the others usually read as imitation and not iteration or improvement.
I don’t generally go for the pirated stuff. I’ll print proxies, but I give GW my money for the IP that I dig.