This would be of limited use for many people. Carriers lock people in by selling lots of phones that are missing frequency bands and cannot be used on their competitor’s networks. For instance, many of TMO’s phones cannot be used on AT&T and Verizon’s networks. My Oneplus 9Pro is a great phone, but if I wanted to switch to Spectrum (on Verizon’s network) or AT&T I would be forced to buy a new phone.

Some phones like the Iphone and Pixels are compatible with every U.S. network, but plenty of others are not.