If the enemies are so far below my players that, if not for a 1 being an automatic failure, they could even roll a 1 and still succeed, I don’t even have them roll. Like if a player wanted to stab a random villager, they can just go ahead and do that; non-adventurers usually aren’t even level 1.
The one time I had a big swarm of weak kobolds in a cave was with an epic level campaign where everyone started at level 20 and my wizard decided to cast max level fireball into the middle of the room, which collapsed the cave and killed everything.
Of course that player got mad at me, despite the other 3 players begging him not to cast the spell and all 4 of them, including the wizard, passed their rolls to see the cave wasn’t stable. Everyone knew what would happen except the dumbdumb playing the wizard. 🤦♂️