Infinite Banking (IB): I rather think this is a "religious" question. If you believe, then it is real to you and you like the results. If you don't believe, ...
I found and watched 3 very detail, albeit quite similar, IB videos. It was clear their source was the same and all mentioned Nash. I took their examples showing the benefits and how to use insurance and checked their math. It look like it would work. Then I reran the examples simply using a real bank. The bank results beat the insurance.
Perhaps there is some "long-game" that would differentiate IB, but it seems to me that the proponents of IB need to use an example that makes the advantage clear. Perhaps the tax benefits way off in the future might make it worthwhile, but they did not show that.
One of the videos used a car purchase to lead into his main example. It this one, he alleged his banker showed that borrowing for the car was better. He was very convincing, but the math was way off.
The tax treatment if started early enough, might be advantageous, but as I mentioned, that was not in the examples.
Regards,
Charles LeMaire