score:6
With regard to the Schengen area, at least, the State Department is ... wait for it ... wrong. This is what you get for asking one government about another government's laws. They don't always get it right. The actual criteria for entry that relate to funds and tickets are
they have sufficient means of subsistence, both for the duration of the intended stay and for the return to their country of origin or transit to a third country into which they are certain to be admitted, or are in a position to acquire such means lawfully;
There's nothing about a plane ticket except by implication, and there's explicitly no requirement to have it in your possession when you enter.
Now I can't say whether there is some formal line of reasoning that officially served as a determination that you had or could acquire sufficient resources, or whether the Schengen countries you entered have some official policy of letting certain travelers in without inquiring into their means of subsistence based on some other criteria, presumably in the name of using their own resources more efficiently, or whether border guards informally adapt their practices based on their personal experiences.
I suspect that it's one of the first two; "acquire such means lawfully" would, after all, include the US repatriation loan. I can't tell you, however, whether there was some formal determination that this option meets the relevant requirement of the Schengen Borders Code or whether a historical absence of US citizens being unable to afford to return to the US has been formally recognized by any Schengen country.
Upvote:2
A few facts that go some way towards answering your question:
In theory, you could imagine that border guards would spend less time checking visa holders as they have been vetted before even taking a plane and had to submit a lot of documentation to establish that they meet the entry requirements. In practice, this does not appear to be the case (to say the least).
As @phoog noted, holding a return ticket when entering is not even a formal requirement. And yet, I have read about countless consulates (or third-party visa handling businesses) that basically demand that you produce one to apply for a visa and would not be surprised if some visa-free visitors had been challenged about it at the border.
It seems quite clear that you are not an outlier and the rules you are reading about are just there as a tool to be used selectively by border guards, not something you should expect to be enforced thoroughly every time you cross the border.