How was Beis HaMikdash destroyed if  the kohein’s clothing forgave all sins? It helped that Hashem destroyed the building, not people (Zevachim 88).

Concepts: Up until majority; only atones for people who could have stopped it, but not for actual sin\sinner; does not atone for intentional sins; does not atone for people who rely on it forgiving the sin (relying on Rav Zeira or great tzadikim); still needs minor repentance. Also: repenting for victimless crimes and accusing falsely.