One of my best friends in high school was Mexican. He didn’t call himself “Hispanic” or “Latino.” He called himself Mexican because he was from Mexico. I’m not sure how the subject came up, but even over beers in high school, important discussions are occasionally had.
But he said that being Mexican was not the same as being Cuban. He understood the use of the terms “Latin” and “Hispanic,” but his point was that all those countries and their people are unique. They aren’t just, as a certain doctor once said, “breakfast tacos.”
But to a large extent, with exception of Portuguese, they do share a common language in Spanish, albeit with differing dialects. And just as they were unhappy with being all lumped together as breakfast tacos, many Hispanic people take exception to the term “Latinx.”