He had a pretty good run. A lot of great material, mostly early on, and he was able to prove to Trent that he didn't need him in order to be successful. That being said, I'm ready for Manson to stop from working with producers that try to really commercialize the sound, and a modern-day NIN x Manson collab would be sooo interesting to hear. I think that some really great avante-garde music could be made if he made an album produced by Seth Manchester or Bobby Krlic!
He has a very good appreciation for the fine arts. In his best albums he makes many references to beautiful works of poetry and literature with his particular character's anti-hero spin on it. As to whether this alone makes him a "genius" is up to you to decide, but after speaking with him many times I've concluded that his "genius," if any should exist, is probably subconsious.
Also, it's a fucking miracle he's still alive. He has a severe addiction issue and he's had it for more than half his life now. Manson, if for some reason you can read this, please, you have many friends and family that love you. We don't want to see you die an early death. Many great artists have created their greatest works much later in life, you easily have another 30 years of creating amazing art ahead of you if you get healthy.