In Jordan's day there were hardly any defenders his size who could hang with him. A 6'6", 220lb shooting guard was huge back then. Nowadays there aren't just a lot more tall, athletic guards, but there are a lot more athletic defensive stoppers with size who can give problems to elite twos.
With good team support, even slender 6'3" guys like Dumars and Payton were able to control Jordan to an extent (look at his numbers the last three games of the 1996 Finals). But too often he was facing slow/old guys like Hornacek and Ehlo and Majerle, or little guys like Scott and Starks. Or skinny Reggie. The number of Jordan defenders who couldn't break 180lbs is ridiculous, and most of them did NOT make up for it with elite technique.
Not to mention the lack of zones created real problems for help defense.
I'm not saying Jordan ain't the GOAT. But his accomplishments are a bit inflated by the weakness of the guys he faced. Nowadays there are a dozen or more players who could make him work at least as hard as Payton/Dumars did, and the fall-off after them isn't nearly as bad as it used to be.
Hell, JR Smith ain't going to make an all-defensive team in a million years today, but he's 6'6", 225lbs, athletic, and can play hard on D. How many guys like that did Jordan face, ever? You had Drexler and...?