The problem is ideology. The Texas power grid is the end state of neo-liberalism taken to the extreme.

The belief that natural monopolies should be privately controlled with minimum regulations has lead to this. A power grid run for maximum short term profit with minimum investment. The grids poorly maintained, because that doesn’t make money. The grid is unfit, because implementing designs that cover the extremes is expensive. The price is excessive because the state is ideologically unwilling to intervene.