Here in California I’ve had fun correcting the hackneyed “English” of the various maroons who my son had to endure in high school.
The mathematicians were the worst. They were astonished when I would correct both their grammar and their math which typically had multiple errors. They aren’t used to being criticized - their customers are teenagers conditioned to thinking they are gods.
The smart people in college get jobs in the private sector and non-educational parts of the government. The smartest teachers get stomped on by the dimbulb majority who get the job because they aren’t going to get one elsewhere.
Illiteracy is just the tip of the iceberg.
Them that can, do...
You know the rest.