The same workers who can build gas and oil facilities can build wind and solar facilities, so Texas had a workforce ready to build renewables.
Texas’s electricity system allows the cheapest producers to win the bid, so as long as someone built the wind or solar, they could beat out the pre-existing facilities.
Texas built a lot of transmission lines.
Texas had a lot of natural gas power plants, and these plants can ramp up fast, so they can turn on at night after the sun goes down.
Texas also had both good sun and wind to harness in the first place.