Anyone whose been in Dallas in August when it's been 110 degrees with humidity at 80 percent 3 days in a row knows why Texas cannot become ... anything but Texas.
Silicon Valley was not an intentional construct. It was a happy, chance collection of attributes that were combined geographically and then allowed to evolve for, now, 100 years. The Valley's seeds were planted in the 1920s when the Stanford-graduated, radio-enthusiast, electrical engineer sons of John Osborne Varian[0] patented the vibrating magnetometer. You you might consider John Osborne Varian the 'father' of Silicon Valley. His sons, Russell and Sigurd Varian, were compatriots of Philo Farnsworth and later invented the Klystron and founded Varian Associates.
Radio technology, a key player in WWII, guided military dollars to Silicon Valley. And then, Shockley established the semiconductor industry. Happenstance again due to Shockley being an alum of Bell Labs, and born in Palo Alto.
The point is, it was chance that the Varians and the Shockleys were from a region that included Stanford University. And to some extent the weather may have played a part in their decisions to locate their companies there. The seeds were planted as a matter of chance and then allowed to grow, mature and evolve for now 100 years. Moreover, I'd contend that the rate of growth in influence (how would you measure it?) of Silicon Valley is greater than anywhere on the planet, meaning, there is no region that is closing the gap.
Texas is a great state. It has awesome people, a large space industry including NASA, SpaceX, Virgin Galactic, the real Texas Barbecue, a great University system, and a significant high-tech industry. But it cannot be, and should not strive to be Silicon Valley. It should strive to be the place that it has the most natural advantage give it's history, resources, and strengths.
To put it succinctly, Texas should not strive to become Silicon Valley any more than Silicon Valley should strive to become Madison Avenue, Hollywood, Las Vegas, Paris, Milan, ...