I've always thought Demar Derozan is a upper end comp for Jaylen. He has great tools, as does Derozan, but I'm not sure he has quite the feel, instincts, etc. to become a super duper star.
I could see him making steady incremental improvements each year like Derozan did, but maybe never quite being that franchise altering talent like Kawhi, KD, Towns, etc.
That would definitely not be a bad player to have for many years into the future.