Yeah, there is plenty of blame to go around. Ultimately it’s Travis Scott’s event. It not like Astroworld was just a random festival that he was playing, essentially his name is on the event.
Other events off the top of my head, the Roskilde Music Festival back in 2000 when festival goers were crushed to death during Pearl Jam or Woodstock 99 when a handful of people died you could argue that the artist in those instances had very little to do with the actual deaths since they were not actually the event organizers but I would think it’s safe to assume that this event was organized completely by in coordination with some company attached to Travis and since it’s his promotion and he’s preforming the Buck ultimately stops with him.