Many of us are most likely gulty of this or have been guilty of this in the past. For some Neurodivergent people who are rule driven it can be almost painful to not correct grammer or a misspelled word. However by doing so one upholds white supremacy (colonialism), for its racist, ableist, and classist. Being white I clearly cannot go into the racism of it overly much, I do suggest following BIPOC pages on facebook or twitter to learn more or read the information on AAVE (African American Vernacular English) and AAE (African American English) and to take cultural differences into consideration.
It is ableist, because of the fact that learning disabilities (which fall under Neurdivergencies by the way) can affect ones ability to spell and use grammer, or just poor executive dysfunction can impede ones abilities to access those skills. Its also classist for not everyone has the same access to education.
More on it upholding colonialism :
Article one: Grammar Policing as colonialism
Article two: Consider This: Colonialism in Grammar Police