This would allow for renewables (mainly WIND in Texas) to be sold out-of-state, and would also mitigate peaking events (e.g. winter 2021 disaster) – this would reduce the need for in-state peakers (instead: buy power from another US state).
But as the saying goes: "everything is bigger in Texas" – including the self-induced isolation. Doing this would require Texas to submit to federal energy regulations... which I'm doubtful will ever happen voluntarily.
src: retired Texas datacenter electrician (IBEW)
[0] <https://en.wikipedia.org/wiki/North_American_power_transmiss...>
[Texas' isolated grid operator:] <https://www.ercot.com/>