A lot of sarcasm here, but I fail to see how deregulation or Texas’s separate grid contributed to this problem. I see two main contributing factors:
The storm wasn’t projected to hit Houston this hard. The projected track had it making landfall way down the coast in Corpus Christi just 48 hours before, and the day before that it was projected to hit Brownsville, a solid 350 miles away. Houston was not projected to be the target until the last minute, so many people were caught unprepared, including Centerpoint Energy.
Houston’s tree canopy is massive. Sure, Houston has a ton of concrete and deforestation, but it remains on the edge of the Piney Woods, and especially in north and east Houston many areas are completely blanketed in hundred foot tall loblolly pines and sweetgums that are prone to breakage in hurricane force winds. Power lines were shredded, and many homes were damaged by falling trees