This happens every time.
Y'all have these big dreams for fictitious characters and are suddenly shocked when your headcanon doesn't come true.
Let me tell you something.
Luffy got CLAPPED by Kaidou at the beginning of Wano.. Did Luffy fans give up?
Sanji got clapped by Doflamingo despite using his best attacks.. Did Sanji fans give up?
I do not know what you thought would happen here, either, as Kidd is literally up against one of the most hyped Yonko members ever bar Kaidou. It was clear he wouldn't win. Perhaps this is a brutal defeat, but this is the defeat of a guy who murdered innocent people for no reason.. Still think he didn't deserve it?
Not to mention that Kidd needed to jump an Emperor before and had only won because he got lucky and threw her out of the island. And Big Mom is cocky. Shanks is serious. That's the difference.
They're out of the playground, they ain't playing soccer on the playground anymore, this is hardcore Rugby.