If you're looking for a better reason for creating a personal email account, think about this:
One day, maybe soon or maybe years from now, you will graduate from this school (or stop attending here). When that happens, your school accounts will all be deactivated.
Which means, you will lose access to them.
So, imagine starting a DoorDash account with your school email address. Then, one day, years from now, after your school email account gets deactivated, you forget the password to your DoorDash account. So, you click on 'Forgot Password' and the email that gets sent for you to reset your password goes where?
To your deactivated school email address. The one that you won't be able to access.
Now, imagine creating that DoorDash account with your own private email address. Then, one day, years from now, you forget the password to your DoorDash account. So, you click on 'Forgot Password' and the email that gets sent for you to reset your password goes where?
To your personal email address. The one that you will still have access to in the future.
Because personal email accounts stay with you, and school email accounts do not, they are the proper choice for trying to build a lifetime of access accounts.
Creating your own personal email address is easy and free.