Separation of duties or segregation of duties

It is a principle of having more than one persons required to complete task.

Why we need to follow this principle:

if an attacker steals one person's credentials, he still won't be able to complete the task because he need to steal credentials of second person too. And it prevents sabotage, misuse of information.

References

1. (Microsoft 2021) , https://techcommunity.microsoft.com/t5/azure-sql-blog/security-separation-of-privilege/ba-p/2393637
2. (Wikipedia, 2023) https://en.wikipedia.org/wiki/Separation_of_duties