I like Zoro, I really like him.
Even in the most optimistic case, even if Oda goes mad with powerlevels like Toriyama as the story goes on, I think that the right hand of the new Pirate king being stronger than the old pirate king himself would be meaningless, incoherent, unnecessary and unrespectful of 23 years of writing.
To my eyes, it would be like Sanji being equal to Rayleigh.
I mean, we're in the Yonko saga right now and anyway Luffy, the future pirate king and stronger than Zoro (future means like 4-5 years in reality, some months in the OP world) got oneshotted by Kaido, who's inferior to Roger. How you justify a this kind of choice?
And I really like Zoro
The Strawhat crew will surpass Roger's just because they're born 20 years later, in the perfect time for the Dawn
to come, not because they're overpower (the contrary scenario, for me, would add nothing to the opera, maybe would make it worse because of the incoherence in developing such a growth in powerlevels now unpredictable)