When Texas and Florida are as congested as New York and California, the COL will also rise proportionately.

Florida already has a higher population density than either New York or California:

en.wikipedia.org - List of states and territories of the United States by population density

It is certainly true that Florida lacks any individual cities that are as dense or congested as NYC or SF (though the Miami/South Florida metro is roughly the same density as the Bay Area). Partially that's because we're relatively new to a large population - most of the state was developed long after the invention of the automobile. But...that's also an inherent difference in the blue/red model of state and local government. Progressive areas take steps to encourage denser development patterns, promoting mass transit and walkable areas and planning systems that create specific types of urban form. Conservative areas practice more of a 'benign neglect' when it comes to urban and centralized planning, which results in more sprawling and less dense types of communities.

Places like NYC and SF bring a lot of benefits - in a "spiky" global world, they create enormous opportunities (and not just economic). But those places end up being very unwieldy in a lot of ways. They can't function without a massive coordinated and collective (read: public government) effort to keep them running. Most red states are choosing not to create new extremely dense urban areas, and Florida's been a red state (at the state level at least) for twenty-five years now.