[parsnipsumthing]

The E-2 is a non immigration visa without dual intent. So... just like an F-1 student visa which is a non immigration visa without dual intent.

All this means in reality is that once you've come to the US and established the basis for another visa, your "intent" changes and you apply for an applicable immigration visa. People do every year with both the F-1 and the E-2 visa.

However, some people prefer to reside in the US long term with non immigration status. The E-2 allows people to emigrate to the US and remain there, indefinitely renewing their E-2 visa, whilst (i) protecting their future non-US tax status, and (2) entering and exiting the US for long periods of time (as long as the business is operating successfully). This contrasts with a green card, which (i) subjects green card holders to "citizen-like" tax obligations after a specified period of time and (ii) typically requires continuous residence in the US.

The continuous presence restriction would lift upon receipt of citizenship but not everyone wants (or is able) to hold dual citizenships.

An E-2 is just fine for many rich people.