> W-8BEN has nothing to do about dealing with US companies or government.
> If you open investment account to buy any US stock, index funds or a some other US-based financial instruments you have to fill W-8BEN
You seem to directly contradict yourself. Dealing with any US-based financial instrument obviously has to do with dealing with something US related.
In contrast, if I only invest in any non-US financial instruments, I don't have to deal with W-8BEN.