AC transmission absolutely does work over large distances. It’s just not a point-to-point system.

Imagine four cities in a row, all connected with AC. City A generates extra power, which gets sucked up by city B, whose power goes to the next city down the line, to city Z.

Sure, it’s not actually that simple, but when was the last time NY literally had no power? They benefit from being highly connected.

TX is paying for being isolated.

Their handful of DC interconnects do not have the capacity to power their mini grid. They’re short 35GW of generation, and I assume the DC ties are at capacity.