Embiid is on a different level than Gobert and KAT in my opinion. I'm not sure PER will tell the story with that one. I'm not sure the Boston series will tell the story, either, as I don't think he played that well and had his weaknesses exposed. In some respects, he's definitely been crowned prematurely - his per possession numbers are somewhat inflated by the way his minutes have been managed. Durability and conditioning are major concerns where they aren't for a player like Towns, whose superior offensive game allowed him to drag a sad sack franchise to the postseason at the age of 22.
But the distinction between star player and generational player is an important one, and it jumps off the screen to me every time I watch Embiid play in a way I haven't seen since LeBron. The way he completely transforms the floor on both ends is difficult to qualify unless you're watching him and only him every possession. Go back and watch game 3 of the Miami series, 4th quarter. Absolutely dominant.
LeBron was a much better player at age 24 than Embiid was, so the comparison needs to be made cautiously. Davis is certainly a better player at this point in time. Cousins might be - unfortunately, he's yet to find to the right situation and I worry that he's been stigmatized as a result of the disfunction he's endured. Replace Embiid with a healthy Cousins and I think Philly goes to the finals. He's that good.
In terms of size, touch, and instinct, though, LeBron's the player that comes to mind when I watch Embiid. I think the numbers - on/off splits, synergy data, adjusted +/- - bear that out. He's not tracking at the same rate as LeBron or any other great that grew up playing the game, but he's starting from a similar foundation of physical ability. The one question is durability.