One thing that's cool about Go is that the pieces get their value and power not from the rules, but from how they are used. In an actual game of Go, you will find groups of ten pieces that are casually thrown away, and you will find single pieces that the whole game revolve around. In the rulebook, they are the same piece, but in actual effort expended to save/attack them, you'll see they're valued vastly differently.

This happens in chess too, of course, but in Go their value is decided only based on how they are used. The sophistication is about the same, but the rules are simpler.

Actually, that's the draw of Go over Chess for me. The different powers in chess seems arbitrary. We can easily imagine aliens coming up with Go by convergent evolution, but not Chess. Too many free parameters.

Yes, the fascination lies in the strategies that emerge from the simple base.