I understand that. But the fact of the matter is, Zoro didn't. Could Zoro have survived that depth? The answer is unknown, saying he can, and saying he can't are both equally wrong and equally right. That means both are inapplicable to Zoro's durability, one cannot cite him not leaving the bubble as proof that he didn't have the durability for it, but one also can't say that he could have because nothing has indicated so.
The thing is, Sanji did leave the bubble, which means that he has that feat, and Zoro has no greater durability feat than that as of yet. It's not an issue of can Zoro match that feat or not, the simple fact of the matter is, he has not done so, so we cannot say he can. As per manga feats so far, Sanji is the more durable of the two. Just because Zoro arguably had more durability during part one doesn't mean that's gonna stay the same in part 2. Smoker was beating Luffy in part one, is he beating Luffy now? Coby had better Haki than Sanji in part 1, would you bank that his is better now?