NCLB original intent was only to point out deficiencies in the education. Everybody complained that the US was getting behind, but there were no absolute solutions. GWB and Ted Kennedy got together and came up with the program to locate deficiencies. Originally only tested language arts and math. Deficiencies were located at particular schools and races. The states were given opportunity to plan their own tests and design the degree of difficulty. This was specifically established to discourage being used as a comparative. That didn't last long as scores were published and less informed souls began to compare without the degree of difficulty assigned to individual states. Then it got a bit complicated as individual schoolboards wanted tests that satisfied personal wants. What was finally developed was not popular in many settings.NCLB was horribly destructive to curriculum
Teacher evaluations became determined by test scores. Teachers began teaching to the test so as not get their ass in hot water from a poorly preforming class inherited from prior year. Got to the point that outsiders wanted to let test grades determine pay scale. The demise of NCLB was predictable. Keep in mind these tests were in addition to state and local testing requirements. Testing was replacing about a month of instruction time.