If the "Erase" option is greyed out in Disk Utility, it could mean that your MacBook's disk is being used by another process or application. You can try a few things to resolve the issue:
1. Restart your MacBook and try again: Sometimes, restarting the MacBook can help free up any processes or applications that are using the disk.
2. Boot into recovery mode and try again: Restart your MacBook, then immediately press and hold the Command + R keys until the Apple logo appears. Release the keys and wait for the macOS Utilities window to appear. From there, select Disk Utility and try erasing your disk.
3. Use an external drive to erase your MacBook's disk: If erasing the internal drive is not possible, you can try using an external drive to erase it. Connect an external drive to your MacBook, then use Disk Utility to erase the external drive. Once the external drive is erased, you can use it to erase your MacBook's internal drive.
4. Use a third-party utility to erase your MacBook's disk: There are third-party utilities available that can erase your MacBook's disk. Here, I suggest you to try BitRaser File Eraser software that will help you erase your drive beyond the scope of any recovery.
If none of these options work, it's possible that there may be a hardware issue with your MacBook's disk. In that case, it's best to take your MacBook to an authorized repair center to have it checked.
[Link edited by Moderator]
