@Aurius-Blood I didn't say anything about Zoro being as durable as Luffy, I said he he is as STRONG or nearly as strong as Luffy. Luffy has always been more durable by virtue of his DF since the start of the series. That's not up for debate.
The thing is though is that Zoro is really powerful. The only way Luffy stood a chance against Kata was because of future sight and Gear 4th. Zoro doesn't have those things so of course he would lose, that's not what I'm saying. What I am saying is this: With their base abilities: Luffy's DF without Gear 4th or advanced observation and Zoro's swordsmanship, they are capable of the same level of destruction.
Gear 4th and Future Sight essentially act as a "power-up" for Luffy, like Super Saiyan or Kaioken in Dragon Ball Z. Zoro has absolutely nothing like that, so how can he be a match for Luffy? Sanji has a Raid Suit now so he's gotten his own "power-up" but Zoro is still fighting with his base abilities. Both Luffy and Sanji have evolved since the timeskip and Zoro hasn't but he is still keeping up with them. He took out Monet, Pica, the dragon on Punk Hazard all with relative ease and without getting injured. He withstood Fujitora's gravity attack and was able to get right back up and attack him with something the Admiral was forced to defend against. He one-shotted Kamazou and defeated Orochi's ninja single-handedly. All of this he has done without any sort of power-up or evolution. Conversely, Luffy and Sanji have struggled or been seriously injured by almost every powerful opponent they've faced since the timeskip. Hody Jones, Vergo, Doflamingo, Cracker, the Vinsmokes, Katakuri, etc., Zoro is an absolute monster. He has not seriously struggled against an opponent until he got into Wano. Luffy is only more powerful than him because of Gear 4th and advanced Haki. Zoro's raw strength is easily a match for Luffy without those two things. To reference DBZ again, it's like Goku and Vegeta. They are always a pretty much evenly matched till Goku gets a new form.
Now in response to whether or not Zoro could defeat Kata, I don't think so but that doesn't mean he'd fare any worse than Luffy. We saw that Zoro has strong enough observation Haki to find Pica in his massive stone body so it's not like he doesn't have the potential to develop it further. Also if Zoro can imbue Haki into his swords, he can imbue it into his body to enhance its defenses. As far as speed goes, Zoro was faster than a Fishman underwater so you honestly don't believe he's much faster on land? Maybe not faster than Gear 2 Luffy or Sanji because speed is their strong suit but he's no slowpoke.
Bottom line: I urge you to look at Zoro's powers and abilities page on this wiki and get a better understanding of what he can do. It says that he has some of the most impressive feats in the entirety of One Piece. Look at it like this:
Luffy after timeskip
-Was injured by Hody Jones
-Needed Gear 4th to defeat Doffy
-Needed Gear 4th to defeat Cracker and Nami's help
-Needed Snakeman and Future sight to defeat Katakuri
Zoro after timeskip
-Defeats pre-steroid Hody
-One shotted Hyouzou
-One shotted the dragon on Punk Hazard
-One shotted Monet
-Withstood an attack from an Admiral with relative ease and was able to counterattack
-Defeated Pica with relative ease
-One shotted Kamazou
-Defeated Orochi's ninjas
Luffy has barely been able to defeat a single enemy without relying on his trump card while Zoro has been breezing through the New World. Now we could argue about the caliber of opponents each of them has but the truth is that without Gear 4 and advanced Haki, Luffy is probably only a little stronger than Zoro. And if it turns out that Zoro has Gear 4th-like trump card he hasn't revealed yet, then I see no issue with him taking on at least a Yonko Commander with difficulty.