Building interconnects costs money. What's the ROI on building more?

Positive ROI becomes present if Texas has large amounts of nondispatchable power and the neighboring areas do not have the same. So if Texas builds more wind and solar than they can consume themselves, then it makes sense to invest in more interconnection capacity. But that's predicted on excessive production first.

Finally, let's just say they built 70 GW of interconnection, because you seen to think that number is important. Do you think Louisiana and Arkansas have that much generation and transmission capacity themselves? Let alone EXCESS?

Washington and Oregon are on the same grid, with about peak generation of 31 GW and 18 GW, yet only about 7 GW of transfer capacity exists, and it's only that high because of sales to California because of seasonal hydroelectric oversupply, an oversupply which doesn't exist in Texas, Arkansas, or Louisiana.

Significantly higher interconnection capacity does not yet make financial sense. They're right to not yet waste money on them.