That's not what caste is. Caste is a value assigned to you at birth that you cannot change no matter what you do. It's similar to race but stupider

This sounds an awful lot like what money in America has become.

An american rags to riches mythos and a small and decreasing class mobility asymptotically trending to zero looks more like caste than not.

People are having a really hard time grasping this and Im not sure why.

Kind of sounds like "from old money" vs "not from old money" in the UK/US/etc?

It's money and everything that comes along with it - social status, health (both because of access to healthcare, but being able to afford a healthy lifestyle), education, safer interactions with law enforcement, job prospects and advancement, etc. If you're born poor, it's very hard to break out of that. It's not literally impossible like changing caste is, but it's very difficult.

Moving abroad and changing your name may even be a little easier than breaking out of American capital chains. Youll still be dalit but it doesnt have to define you.

India also has a dalit president.

America hasnt had a president of modest income since Truman.

Money, education, Mayflower ancestor, eligible to join the Daughters of the American Revolution, distant relative of some famous or wealthy family, member of some social clubs (even inexpensive ones), and so on.

Edit: but as many other folks are mentioning, this is class and not caste. You'll notice that around half of the things I've mentioned are something you're born with.

Honest question, in what situations have you been in where you were aware that someone had a Mayflower ancestor or was eligible for the Daughters of the Revolution?

That has literally never happened to me.

I don't give a crap about class, so I'm probably not the person to ask. I do have family members who care about it.

and skin color, gender, race or sexuality based on the local politics/religion.

Money and education.