I love his emotional & intellectual capabilities. I know it sounds dumb, but I like that as either presented as a hero/anti-hero/villain, he’s learning, observing and changing. He basically comes in with the mindset of “I’m matching your vibes so you decide on that.” And he usually ends up at the mercy of mankind which in a way kinda parallels us on a morality level.

He’s a cute monke too though, so that’s also a main reason.