"Muhhhh, Shanks has a crew, and that's why his 4 billion bounty is higher."
And the Marines, who have more resources than Shanks and have a lower bounty than him, what is the justification for this immense "L" that the Marines have taken here?
Let's take Kizaru, for example, who has been in the Marines for decades, is part of the original trio of Admirals, and is much older than Shanks. Kizaru has his own squadron, can request as much reinforcement as he wants, and can even request or receive help from another Admiral in his tasks. Does Shanks receive help from any of the Yonko? Can you imagine if Kaido had Shanks, Big Mom, Whitebeard, and all their subordinates as teammates, providing support to him in his daily tasks? That's how the Marines operate, so Shanks being a Yonko and having a team supporting him doesn't mean a damn thing... The Marines' bounties have been directly compared to the Emperors', and even though the Marines collectively have a power that surpasses any Yonko (military power of the Yonko), the Yonko still have a higher bounty.