2-Step Verification (2SV) uses something you have (like a key, code, or phone) and something you know (like a password). Because text messages are sent from an external source they can be intercepted or sent to a bad actor.
Codes you've downloaded or are generated on and by your phone are not sent, they are inherently something you have in your possession, that no one else would have access to.
This option is no longer secure and will be removed soon.
Click the edit icon and select REMOVE PHONE
If you don't have another method set up, you will lose access to your SIL Google Account after August 15.