In my first bands, I couldn't care less about any of that. I can't even remember some gigs because back then I was always extremely responsible about making sure I didn't run out of weed. Those days are long gone, though. Now I consider it a given that everyone in the band is responsible for ensuring that, in the worst-case scenario, the gig doesn't have to be interrupted for more than two minutes. How exactly each person ensures this is up to them. But failing to do so is unprofessional, inexcusable, and ignorant. Especially if you're not the only band playing and there's an entrance fee.