Strange…it's almost like when they first met the Admirals and got a glimpse of our first Yonkou, the Straw Hats were weaker and unprepared for the New World. Could it be....gasp that they've actually gotten stronger? And something like them VS Aokiji could have gone differently?! Surely not!
Heh. If we had a like system, I would give you one.
So I do have to post pages.
This is what WB did after he got pierced by Squardo.
Meanwhile after that, he fought on with a hole in his chest, he managed to deal serious damage to Akainu even with half of his head missing and treated Teach like an utter clown.
Meanwhile Akainu faces off against all of WB's commanders. Vista and Marco included. He makes Teach outright admit inferiority even with his crew at his back.
Kaido falls from the heavens, the shockwave nearly knocks everyone out and we have 4 Supernova, guys far stronger than Brook, Nami and Chopper outright tremble at the mere sight of him. One got wrecked, the other pissed himself and joined him and we have no idea what happened to Hawkins. But we do know that not only Kaido considers the Supernova ants, he showed the true difference in strength that they have. Doflamingo who put Luffy through hell, the same Doflamingo that easily defeated Law, the same Doflamingo that would have easily killed Nami, Brook and Chopper, was sweating at the mere thought of Kaido.
Compare all of those things to Big Mom failing time and time again to do anything of worth, getting stopped constantly by guys that should have not shown any problem to her at all but not only that, when she got in point blank range she got humiliated yet again. But no this is great writing according to you.
–- Update From New Post Merge ---
Surely, while yonkos' strength is a major factor, their navies and territory are the things that make them yonko. They literally rule the seas in the New World.
They are Yonko because of their strength. They acquire those territories because of that. Oda didn't hype their territories, he hyped their strength. He build up on that strength.