I just don't think digitized financial services "scale down" to that level, even with BTC. Some transactions just aren't worth enough to bother setting up the safeguards and equity splits (which, again, have to be negotiated and implemented somehow). Someone will feel screwed, and eventually legislation will arise that introduces the friction back into the transaction.
I'm also not convinced that the low-friction transaction model is considered a good thing globally. The US and EU are the exception with respect to having low-friction transactions: in most of the rest of the world, buyers get angry if they can't haggle on price, even over the cheapest items. It's a cultural thing. Compared to the friction of negotiating price, cash or credit cards aren't that bad.
I'm also not convinced that the low-friction transaction model is considered a good thing globally. The US and EU are the exception with respect to having low-friction transactions: in most of the rest of the world, buyers get angry if they can't haggle on price, even over the cheapest items. It's a cultural thing. Compared to the friction of negotiating price, cash or credit cards aren't that bad.