On 2020 and newer Toyotas the hands-free microphone and the front-right speaker route through the DCM, so pulling the fuse or unplugging the module breaks them. A bypass harness sits between the DCM connector and the factory harness, severs the cellular path, and is designed to preserve the mic and speaker functions that route through the module.
Most ordinary vehicle functions should remain intact, but every Toyota communication-dependent service stops working, which is the point. Verify fitment for your exact model and year before install. This is the fallback when a pre-2020 car is not an option. Disconnecting the cellular and GPS antenna leads at the module achieves the same result for people comfortable with trim removal.