Discrepancy in tech salaries between Austin and Houston

Hey, so I thought that Austin was the tech hub of the south, and was paying higher salaries than any other city in the south because of its tech scene and relatively high cost of living. However, going to the website Living wage calculator shows the average salaries of each occupational area in the provided metro area.

Comparing the occupational area "Computer & Mathematical" between the Austin and Houston metro area, Austin actually has a lower average salary than Houston, which is surprising. I thought Houston had a smaller tech scene and less job opportunities than Austin? Or is there something missing from the equation I don't know about?