Texas' grid was very reliable when I was growing up there. Since deregulation however, it's no longer reliable. It used to be mandated that grid facilities were overbuilt to have some headroom for emergencies. That's no longer true. Now, Texas utilities only maintain the minimum infrastructure needed for normal operations and they have no cushion if something goes wrong. Any CEO of a Texas utility that spends money building overcapacity gets fired by Wall Street.

This was supposed to change after the 2021 crisis, but I haven't seen much evidence that it has.