When coins no longer matter at all

We are nearing the point when coinage becomes irrelevant. Already many of us do most our daily business electronically and have little use for cash.  This will continue and soon enough there will be people who may live their lives having never handled cash at all.  Eventually governments will stop producing paper money and coinage.

That may cause a resurgent interest in coin (and paper money) collecting, but longer term it doesn't bode well.

Except..

There will always be people who want to transact business privately.  Their business may be illegal, or they may be avoiding taxes, or they may just be pursuing privacy.  These people use cash now - we call it the "underground economy".   What happens there when governments no longer issue physical money?

I suspect they'd turn to bullion.  Maple Leafs, Eagles, bars and so on.  That's perhaps inconvenient for large transactions, but it's more convenient than anything else - trading bags of cocaine has more disadvantages than trading bullion.

In 2014, the U.S. mint produced over 44 million ounces of Silver Eagles.  I have to wonder: did all of that go to collectors and stackers?  Is it possible that the bullion underground economy has already begun? Or at least that people are stockpiling in the expectation of that?  In other words, how many people are buying bullion expecting to exchange it for dollars later vs. those who expect that the bullion itself will be their medium of exchange?

Note:  All my coins are in a safe deposit box.  I keep nothing in my home. 

Contests and giveaways: http://coins.aplawrence.com/2014/05/contests-and-giveaways.html