The Texas Constitution is widely criticized, particularly with regard to the three branches of government. If you could change one thing about each of the three branches, what would it be and why?

The current Texas State Constitution was adopted in 1876. Among other restrictions, it stipulated that it could only be changed by amendment. It is also one of the longest state constitutions and uses a lot of dense language. By 1928, 99 amendments had been proposed (less than half successful) but by 2015, more than 400 had been added. Several calls for a new document have not advanced to completion, although there was a constitutional convention in 1974, and in the 1990s two new versions were drafted.
The constitution specifically limits the state's powers to those laid out in the document so it is cumbersome to add any other duties. This is one aspect many people have wanted to change.
A difference from the U.S. Constitution pertains to the executive branch. Texas has a plural executive, meaning that executive power is spread among multiple executive offices, as contrasted to a single person (governor, president). While this helps keep any one person from gaining too much power, because it also fragments the executive, it can be harder to get things done. This is an aspect many wish to change.
https://dlc.dcccd.edu/txgov1-2/two-constitutions-a-comparison

https://tshaonline.org/handbook/online/articles/mhc07