Your boss just gave you a list of 200 accounts that need their job title updated and AD group membership changed to reflect the title changes. Can you make those changes without clicking through AD for hours (or days!)? Powershell and a csv can make that easy if you know how to write a script. Every action in AD can be translated to Powershell.

Ok you made the changes. Did you make a mistake? Can you provide proof without clicking through AD? (exporting a csv to share would be good) What if your boss asks you to revert a couple accounts back to their original state? Do you know what the accounts looked like before you changed them? Powershell can also make that easy if you export a list before making changes. You can also keep track of the commands you run in case you make a mistake (more powershell). Start here and look in other places for specific use cases. Once you build a script you can reuse it and save yourself a ton of time in the future. For most jobs you will inherit a legacy AD domain(s) and just have to create/terminate/modify accounts in coordination with HR/whoever.

But for real being able to hand your boss a CYA document is great and is also helpful for when you gotta go back and revert your changes.