They have the tech, but they don't understand it.
I suppose they do know how most of the stuff works, they need to maintain it themselves. Also, Technocracy is doing some prety groundbreaking research even by Star God standards (while they most likely inherited most od their dimensional stuff from Cyberweb and zombie stuff from M.A.G.N.A., the technomancer is likely of their own design) and Humanists seem to be behind Kruger and Magneto-plasma rifle, so it is not like nobody is doing research either. Perhaps after the UAC debacle, Star Gods decided that humans should stay the hell away form R&D.