That guy is just repeating what he heard on the radio or from some drunk guy at a bar. He’s not putting any thoughts into it.
Besides what you mentioned, there are pre-nups, post-nups, trusts, and other complicated ways that rich families use to protect their assets from gold-diggers. Marriage is a legal contract and it can be modified with other legal contracts.
In a lot of cases, “trust fund kids” don’t even own their house or car. It’s all held in a trust so no one, not even them, can have it. If they divorce there’s nothing to split but some cash and whatever furniture or toys they own.
In practice, I believe the pre or post-nup gives some consideration (money) to the spouse who isn’t rich so they won’t sue. But it’s not 50/50 because the trust fund kid legally doesn’t own much.