What to do when archive logs are lost/corrupted that are not backed up
As soon as your recovery thread is interrupted, making it impossible to recover from an earlier backup to the current time, the remedy is to take a backup before something more serious happens.

Next investigate how the archives became corrupted and solve that.

Backups are of no importance, important is the ability to recover from a disaster and for that backups or physical standby databases can be very convenient to have.