[cedilla]

It's a thought experiment. It's not about envelopes of cash, it's about logic and game theory. Their usefullness can hardly be overstated.

But for what it's worth, there are a ton of thought experiments inspired by or lifted from the real world. The Monty hall problem is taken from a game show - it even has a contestant who must choose one of three doors...

[GeorgeRichard]

Why is it a thought experiment? After all envelopes, cash, experimenters etcetera exist. It could be a real experiment. On the other hand what theory or hypothesis would it be testing?

What’s the problem with Monty Hall? The solution (switch to the other door) is demonstrably true. I believe it’s called a veridical paradox.