* i edited the questions to include the info behind them *

There are several things that i would like to understand from the Americans in here:

1- labeling people, like every American has a set of labels that identify them, like ( race, skin color under a certain race, religion, sexual orientation, etc) and almost every group of people have their own culture, and you don't see that in other countries even with countries with a high number of immigrants, and ethnicities, people don't identify themselves by race or religion and so on so why is this an important thing in America?

2- why is tipping necessary? 🤔 ( there are countries where u must not tip and its actually considered rude to do so and workers will refuse it, and some other countries tipping is okay but optional) i say this because i have traveled alot and I've seen this.

3- is it true that American schools don't teach world history, geography, etc so people are not really aware of other cultures and information related to other countries? ( i say this because I've been told that many Americans aren't really knowledgeable about other countries and cultures, and i have also watched a few random videos on YouTube that confirmed that, and some Americans said that it's because of the lack of offering those subjects in schools.

4- many don't go to university after high school, is this related to the quality of education? Or is it a cultural thing? Or is it related to the costs?

I'm genuinely interested to know those things, so i would appreciate it if someone explained.