Dropping state mask mandates didn’t mean no Covid mitigations. Many businesses continued their same policies. From friends and co-workers I know in the Houston area not much changed when the gov dropped masks. Most businesses continued to require them as well as most employers. That hadn’t started to change until recently with the new CDC rules for fully vaccinated. That’s part of the answer.
We also have 3 highly effective vaccines and 56% of the adult population in TX has been vaccinated with one. As
@Abs pointed out above the urban centers in TX are even higher than the state average and that’s where population density comes into play. So when you combine the vaccination rate with the natural infections there’s a high level of immunity there even though the state level is below the national average. That’s the other part of the answer.
The biggest risk is there are pockets where large numbers of people are unvaccinated that could result in a localized outbreak. I am hopeful that at this point we are far enough along that a statewide spike won’t be long lived or dramatic if it happens. I will feel better about that if/when we get some more people vaccinated. Keeping my fingers crossed