The economics of the above only make sense for products low in bulk, high in intrinsic value, and, importantly, which can withstand the ordeals of the trip. You ship the concentrated juice and not the fruit; the bacon and not the hogs.
with modern globalization, it is cheaper to grow oranges in Brazil and ship the resulting orange juice concentrate 8,000 miles to Australia than to buy orange juice produced from Australian citrus trees. The same is true of Canadian pork and bacon compared to their Australian equivalents.
I guess the only thing less bulky than a SAML assertion is an X.509 cert but historically these haven't travelled well - they start to rot in their containers round about the Equator.