"Can you please provide widespread proof of "income streams vanish[ing]"?"

Were you in a coma from 2007-2010 ?

Ok, let's stipulate that you were. You were in a coma. Fine.

How about twentieth century world history from high school ? Great family dynasties all over the western world were ruined in the aftermath of WWI.

How exactly would you hedge against the leninists arresting you and killing your entire extended family ? Remember, WWI is going on in the background so you can't just jet off to St. Barts...

Moving on to WW2, how would a "prudent investor" manage their portfolio of businesses and contacts and resources in their family base of Dresden ? Or Hiroshima ?

Your scope of thought on this issue is ... limited.