Yeah WB was definitely > Roger when he became Pirate King, but the mere existence of WB in the first place proves that the PK doesn't have to be above everyone. To become PK you need the stars to align. Whitebeard was as strong if not stronger and yet would never even have known about Raftel. Roger would never have become PK without Oden or VOAT. Neither are strength-related.
However, we've been told that Luffy wants to surpass the Yonkou and Admirals so he'll definitely end up above all of them. This is a shounen so that much is obvious. Maybe he'll even surpass Blackbeard and become the strongest Pirate. This one will probably be less obvious seeing as how Luffy always gets lucky in his fights but they'll probably end up even. Rogerbeard will be surpassed through Luffy's actions.
And then beyond that you have unknown factors like Im and the Gorosei, specifically Im who could turn out to be some kind of Kaguya-type figure so I don't really expect EoS Luffy to be the strongest in the verse honestly. But he'll definitely be the strongest among his peers.
I mean the only person in Luffy's clique who we know has that kind of potential is Sabo and even he was slightly behind Ace as kids so he'll probably come close but not quite equal. Law will be a cheerleader, Kidd could maybe contest depending on how he's treated later in this arc, Zoro would have to stop fighting chumps and passing out, Smoker hasn't been relevant since pre-TS and lmao Captain Coby has no chance.