80% Verstappen’s fault that, having watched it enough times. He’s a long way back and on the outside as they enter the braking zone. He’s only able to actually attempt going around the outside because Lewis is fair enough to leave him a car’s width (unlike he did to Bottas a couple of years ago). By the time they’ve taken the first part of the chicane he isn’t alongside and should back out and concede that he won’t be pulling it off.
Thing is, Verstappen wouldn’t have tried that on anyone else. His singular focus on his position relative to Hamilton is intense to a fault. It was the same with Senna, how he used to view everything through the lens of overthrowing Prost and how he used that framework of viewing the world to go about his racing.