Who’s the better rival? Probably Kidd, since Blackbeard isn’t a rival lol.
Kidds role is to be Luffy’s rival from his same generation who climbs up the ladder alongside and competing with Luffy, while Blackbeard is supposed to be his arch nemesis and the greatest Pirate obstacle he must surpass before he achieves his dream. Kidd might not be stronger than Luffy or even equal, but most shonen rivals aren’t equal to the MC, they are usually a step behind which drives them to be stronger. The point is that Kidd will not be a Pirate who just steps out of Luffy’s way unlike all the other super rookies on Saboady.
Another key point of a rivalry, especially in shonen, is mutual respect. Because Blackbeard is so dishonorable and goes against a lot of what Luffy stands for, there is no respect between the two. Just animosity. (Which is why BB is the arch nemesis). With Kidd, while Luffy and him clearly get on each other’s nerves, there is respect. That is because Oda is trying to show that no matter how much y’all love to downplay him, he’s worthy of being someone Luffy thinks of and respects as a rival (we’ve already seen plenty of traits Kidd has that makes him a respectable competitor to someone like Luffy). This won’t change post Wano either.
Other than the usual Kidd bashing, what’s the point of this thread? Blackbeard and Kidd serve two different purposes. Blackbeard might be more impactful in the long haul since he’s meant to be the main antagonist and highest wall Luffy must climb, but everyone with a brain already knows that. Doesn’t take away from Kidd at all since that’s not his role...