It's honestly funny how bounties doesn't matter that much if we're talking about power levels, such a great concept to show characters strenght. Even here Bellamy 50 mil was still more worth than current 100-200 millions. Like Jack he was worth almost same amount as Katakuri but power gap was immense, just because Jack was more brutal and Sturdy he got same bounty
Not really jack was durable as fuck remember he never really had a break since zou which he invaded 2 times after he fought for days while katakuri got knocked and was never seen again Katakuris obs haki made him superior to the others and his versatility in fighting In a 1v1 fight would kata win but he would need time to rest while jack would just stand up after an hour of sleep
