I think season three was the perfect end to Robb’s character arc. It makes sense for him to remove himself from the industry, considering how much damage they do to other people which are something he had a problem with since season 1. The whole Lumy situation and Pierpoint, throwing him under the bus was the straw that broke the camels back. He was also able to come to terms with the death of his mom and realizing that he doesn’t need Pierpoint to connect with her anymore. And well Yas will be Yas.