Yes, you can add additional security onto your account - at least with Verizon. I highly encourage everyone to do so. Once enabled, you will need to present photo ID at a corporate Verizon store to allow your phone # to be transferred to a new carrier.

Instructions: https://twitter.com/ramsey/status/1235227940054585344

My wife got SIM jacked just a few weeks ago and we got extremely lucky that it didn't turn into a bigger problem. They did get a hold of her Venmo account, but fortunately it's not actually linked to our bank account (Venmo restricts the # of users that can link to a single bank account).