When I was young boy I hunted with my 870. The black stock was often brown from the muddy trails an my lack of attentiveness. One time some grit got in the action and cause the feed ramp to jam. It was a cluster that would be hard to clear in a gunfight but that’s all I’ve got. What could catastrophicly fail? (Actual question I’m not baiting you)
It’s rare, but action arms have broken. I’ve also seen feed ramps fail. That’s more common. The cheaper shotguns have binding issues with the action arms. IIRC, the maverick shotguns people love only have a single action arm.
Even if an auto had a gas system failure, you essentially have a straight pull shotgun using the charging handle. You could manually feed rounds if you had to. If the action in a pump fails, you’re out of luck.