Big Meme can't kill Marco, she can't even kill the weak Trio
Pell. Enel. Wyper. Dofflamingo. Luffy. Law....
Big Mom not killing Marco is obvious.
Starting from Whole Cake Island Arc, how many times the Straw Hats survived due to plot ?
-> Luffy need Nami to survive Cracker.
-> Pekoms survive due to Fishman Pirates
-> Luffy and Nami are prisoners of Opera
-> Brook is captured by Big Mom
-> Brook and Chopper are captured by Perospero
-> Germa and Capone survive Big Mom due to plot
-> Luffy didn't die against Katakuri because he choose to pierce his body to have a more equal match.
-> Straw Hats and Heart Pirates survive Kaidou beam due to plot
-> Luffy and Kidd are not killed but taken prisoners
-> Queen is not killed by Big Mom