Verizon around the Nexus 5 still had a lot of CDMA and you needed to have a phone activated.

Now that networks are pretty much LTE and 5G only, if your phone takes a SIM, take the SIM out of the old phone and put it in the new phone. Some carriers still play games with allowlists for VoLTE though.

But you might have better luck (and better pricing) with a MVNO or the prepaid side of your preferred carrier.