The energy prices are low because Texas has tons of oil and gas and wind. The energy grid is actually more efficiently managed than California, which has had similar problems with electricity supply.
But the main reason Texas comes up is it has a very long history in semiconductors with a big workforce and lots of semiconductor companies.
Efficiency in electrical grids can often be counterproductive to reliability.
It is economically efficient to not winterize your generation capacity or build longhaul electrical transport infrastructure to move electricity regionally, but without these rarely used elements you could end up with severe load shedding or a black start event.
But the main reason Texas comes up is it has a very long history in semiconductors with a big workforce and lots of semiconductor companies.