Bounties literally completely lost any value the moment that we know that characters who are canonically much stronger than other characters (and also have canonically greater achievements and canonically much stronger underlings and greater numbers) ... still can have the same exact bounty
Luffy did in 1 vs 1 against a stronger character what Law and Kidd did in 2 vs 1 against a weaker character (needing also an external deus ex machina) -> Luffy is much canonically stronger than them, acrually it's very easy to see him as twice times stronger than them, due to the comparison of their fights
Luffy's previous bounty was 3x times greater than their ones -> he canonically has greater achievements than them, and it doesn't make any sense for this to be suddenly erased
Luffy has far, far stronger people under him than Kidd and Law do... even if you put Kidd and Law's crews together they still are much weaker than Strawhats! I don't care if Zoro is slightly stronger, exactly on par or slightly weaker than Law and Kidd, think as you wish, but he alone is comparable to them (and as future WSS, defeating someone who is at least a peer to Shanks, he is bound to be comparable to them, and like it or not, Oda thinks Law as a swordsman so...), then Sanji is now even stronger than Killer, and Jinbe plus the others would just maul Heat, Wire, Bepo and the other fodders
Luffy also has immense alliances and territories over the world which they don't have or at least not in a even remotely comparable way
Luffy is also Nika/Joy Boy, the nemesis of the WG, plus a D (Tenryubito's arch enemies), a Conqueror (great potential) and Dragon's son (Dragon is the most wanted man in the world). And this is not kept a secret from the WG, Nika is even on Luffy's wanted poster.
With all this kept on mind... no person with a working brain can say, without immense bias, that bounties make sense.
Oda just made 9 billions (Kaido and Big Mom's bounties) split by the three people who are captains of the alliance that did struck them down. Nothing more nothing less. No particular thoughts, on the opposite he literally didn't care for anything, he just split the 9 billions and that's it, even forgetting previous bounties.
Calling this power level related is just a desperate attempt out of pure hate and bias.