@playa4321 boundman tossed Katakuri around too. Matching boundman in physical strength, especially for high tiers, is impossible. Especially for those who aren't ancient Zoans. It was Doffy's mistake to try and go into CqC with him.
Would current Zoro struggle against Doffy? Absolutely, I think, given Doffy's wayof fighting. Staying mid air from long range while spamming a city worth of strings from all directions while controlling the ground and restraining him.
Not like Zoro would just walk through it and one shot Doffy with a clean shot. Given Doffy could stitch together his organs that got torn into pieces, he could even reduce the damage from Zoro's attacks by stitching the wounds together.
Inb4 people say Zoro will split Doffy into pieces. That is not going to happen unless he has a clean, free shot to the neck or limbs. And we know Doffy could do the same with a clean, free shot (like he cut off Law's arm).
People just tend to underestimate the opponents Luffy beat. It's the same with Katakuri, where he is suddenly the weakest YC1.