If you're starting a new franchise, would you rather have a 20 year old Duncan or a 20 year old Embiid?
It might but that's not the reality we live in is it? If Embiid had all of the durability in the world he'd be a top 3 player in the NBA. That being said, Duncan was an absolute monster when he was the Spurs' anchor before Manu and Parker reached their respective primes.
Duncan tore his meniscus at 24 and still managed to become a top 10 player all-time. Without that injury, maybe he's the GOAT?
This is pretty damn close to asking, "what would you take, a kick to the balls or a million dollars?" Embiid is NOWHERE near Duncan. Duncan is arguably the greatest 4 to ever play the game.
I think looking only at their raw talent and nothing else, they're comparable. Both DPOY level players. And you could argue Embiid is more versatile offensively.
Even when not injured, Embiid only cares so much- he remains very out of shape. And Duncan would never go to a concert and dance when "too hurt" to play.
Duncan might be the best 4 to ever play the game. Embiid might not even be the best 5 in the game, today. It's arguable.
Duncan is a top 5 player all time. Embiid is fat and has no discipline. Not even close in my opinion. Tim had the mindset of a champ and Joel has the mindset of a millennial.