(This is not financial advice.)
I’m not sure the linked article shows it to be false, exactly. If you look at the first graph, you can see that over 135 years of US data, 1x leverage returns about 4% annually, and 2x leverage about 5%, with double the risk. That’s pretty bad, unless you’re desperate for risk.
Now, that plot doesn’t include dividends, which are an important part of the calculation. And using different countries or time periods will give different results, as they demonstrate later on. Still, if you’re discussing a type of investment the SEC specifically warns people about, there might be more to say here?
Most Western countries levy some form of CGT; to avoid it, you’d need to move to a low-tax jurisdiction like Switzerland or Singapore. It’s certainly possible for founders and investors to do that, but it’s a pretty big life change.
Moving from one US state to another, on the other hand, is pretty easy.