Queen the Plague is an incredibly powerful pirate and it's repeatedly stated he's a powerhouse in the above 1B bounty level. This alone makes him peers with
Charlotte Katakuri, King the Wildfire, Marco the Phoenix and
Post-WCI Luffy. I don't think he's superior to any of them, but I think Queen the Plague is able to push all of them to high difficulty in a standard fight. (
Luffy is questionable given his showings.)
So there's absolutely no shame with Queen's bounty being close to King the Wildfire's. However I do feel like plenty of this thread is misunderstanding bounties. It's not
just individual strength but
also danger level, as Aokiji stated.
And as far as pirates go, I don't think there's many that can surpass
Queen the Plague in terms of threat relevancy to the World (
Government). The Mummy Virus itself spreads incredibly fast through touch, causing regular fodder to collapse in moments after getting exposed to it, causing them to profusely bleed alongside having their bodies burn up in high temperatures.
Not only is it fast acting, even someone with a mythical zoan and known endurance freak Luffy was reduced to this state in the span of 6/7 pages—intervening when Babanuki tried to up the dosage by x200, saying the future was "pretty bad".
(Luffy under the effects of the Mummy Virus for 6 & 7 pages, possibly a minute in real time)
He looks a little worse than Luffy did after round 1 of Boundman in Dressrosa;
(Luffy in chapter #786 after fighting throughout Dressrosa and the 1st round of Boundman)
So in the span of possibly a minute, one of Queen the Plague's namesake biological attacks was able to nearly kill Luffy. If it wasn't for Chopper, he'd be dead. That is an example of Queen's danger level. You need to be either Law, Vegapunk, Chopper or possibly Judge/Caesar to effectively counter Queen.
The Ice Oni is an even greater example of this. Queen the Plague was screwed over by his own sadistic nature and the plot when utilizing it.
- If Queen hadn't tossed the singular cure to Apoo, everyone on the Live floor would be dead.
- If Marco didn't mitigate the affects of Ice Oni for a time period, everyone on the Live Floor would be dead.
- If Chopper wasn't a genius and able to perfectly turn 1 antidote into a counter-virus, everyone on the Live Floor would be dead.
I'm not saying this as a cop-out to widen the gulf between King the Wildfire and Queen the Plague, I like both characters plenty and honestly don't mind the notion of them being equals. I don't believe it but if Oda came out and said it in an SBS I'd be pretty alright with it.
But to say that Queen's island ending plagues—
because if he unleashed these in Dressrosa it'd be much much worse than the Birdcage ever could be—have no impact on his bounty would be pretty insulting to his moniker and how frightening they are.
tl;dr
Queen the Plague's bounty is as high as it is thanks to his own powerful abilities but a significant portion of it should be attributed to his namesake biological weapons. It's so associated with Queen it's what he brags about when confronting Zoro & Sanji and it'd be dishonest to pretend his plagues don't have major impacts on his bounty.
