I mean, of course not EVERYONE who knows english in Mexico is rich, but the vast majority? Yeah, they're rich.

"Looking into the issue of the teaching of English in Mexico, we found much the same problem as we did when looking at the prevalence of English in Brazil – social and economic inequality is a large determinant of whether someone in Mexico will be able to speak good English. In other words, the richer and more privileged have far more chance of being able to speak decent English, as opposed to the poor or working class who do not have access to the same resources."

https://howwidelyspoken.com/how-widely-spoken-english-mexico/