A bad tooth itself won't cause death and won't kill you.
But if you have a bad tooth that has a tooth infection along with the bad tooth then the tooth infection if left untreated can get worse and lead to other infections in the body when that tooth infection spreads.
So yes a bad tooth can kill you in a way but only if the tooth infection gets worse and spreads to other parts of your body.
Having a tooth infection that gets worse can also lead to heart disease and other heart issues and could possibly lead to a heart attack.
So teeth problems and tooth infections can also get more serious if you leave it untreated and it gets worse.