CP3 has been the best defender out of star point guards in this era (best since peak Kidd), but like you say Payton is straight legendary so there's still a gap. Payton's size in particular allowed him to blanket guys in a way that CP3's 6' bulldog defensive just wasn't capable of.Payton was a better scorer than CP3.
CP3 was a much better 3 pt shooter than the glove and a better distributer,
Payton’s defense was legendary tho.
I'm meh on whether Payton was a better scorer. CP3 is such a good distributor that he doesn't have to rely on his scoring, he picks his spots. But when he needed to fill up the bucket he did that too, he was a MUCH better shooter than Payton not just from three but from midrange as well. Payton could drive but he wasn't like D-Rose level where he could pick defenses apart with it. Look at their per-100 possession numbers and CP3 actually comes out ahead:
CP3: 27.5 points/100 and 14.1 assists/100 on 51% from 2 and 37% from 3
Glove: 24.0 points/100 and 9.9 assists/100 on 50% from 2 and 32% from 3
You could say Payton's last few years hurt his averages, yet his top season (29.8 points/100 in 2000) isn't as high as CP3's peak (32.4 points/100 in 2009), and they both had the same number of elite scoring seasons. Pretty much the same in the playoffs as well - CP3's averages are better and their peaks are about the same.
I watched Payton in real time, and was he the guy you could really trust to put up 30 when you needed it? I really can't say he ever was. I think they were about even as scorers and I'm favoring CP3 if anything, and then so far as passing/distribution/ballhandling goes you have to give CP3 a huge edge on offense overall.