Except Telus, my local carrier here in Canada, says that they implemented the protocol but they also say this:
"At the time of launch on November 30, 2021, most devices are not capable of supporting STIR/SHAKEN and, therefore, will not display “verified” for incoming calls. These devices will continue to display calls as they normally do today.
Once your device is capable of supporting STIR/SHAKEN, then validated calls will automatically display on your handset as “verified”. No action will be required of you."