Telstra exposed client data last year as well.

By that metric, no one should use any network because I can’t imagine any of them are free from this.

This doesn't just affect Optus subscribers. I use Amaysim which is technically part of Optus but functionally separate besides using the same towers, so this affected me too. Our train communication systems broke down which affected everyone regardless of who you're with, and plenty of shops eftpos machines went down (if they were powered by Optus in some way).

yeah good luck there mate they own a huge chunk of the infrastructure.