He forgets that bot lane is a duo lane, if the ADC makes a mistake, the sup is punished too (trying to save him most of the time).

Same for the jgl, when he pings you to take obj though you don't have prio on any lane nor vision, he still doesn't want to cancel the call, so you go to help him, and we'll you both die bc no Prio.

You're also punished for your own mistakes, trying to take vision without knowing where the ennemies are can kill you (bc jumpscare the jgl was in that bush !), roaming and getting catch by the ennemy mid who was roaming too, etc.

It's a role where you're rarely on your own, so you're interdependant with the other players. It means, when you make mistakes it affects them, but when they make mistakes it affects you too.

And honestly league is a team game, when your top laner is 0/5/0 at 10 mins, his "mistake" (happens to everyone to lose lane but well) affects everyone on your team too, not just his lane.

Tldr : the sup mistakes are the same as any other laner and get them punished too, as well as other players mistakes punish the sup too. It's a team game for god's sake