Times are changing so fast. Just a couple of decades ago we had basic computers, brick phones and money was only made from paper and metal.
Now it seems our whole lives are becoming virtual.
Dating is now done on line, our shopping and with sites like facebook and twitter, even our social lives are lived online.
Once the bitcoin was released it meant that other cryptocurrency wouldn't be far behind.
But where will it all end up, will it be the end for physical currency all together one day?
Will our grandchildren and their children look at their elders and wonder why on earth we ever had to carry currncy about.
Even our current money can be spent via apple pay and contactless, so maybe a few decades from now physical money will no longer have a use in society.
It looks likely that we will move to a cashless society. it's an idea that has been discussed and experimented with fr decades. Recently some banks and politicians have been pushing for it saying that cash is enabling criminals ( https://www.treasurers.org/node/316742 ) but many see that as them wanting to retain power by ensuring every penny spent and earned is traceable and taxable.
Perhaps as they push for their version of a cashless society more and more people will be attracted to cryptocurrency.
I think your right regarding criminal activity, if its all non physical it will stop a lot of crime that is perpetrated to get large amounts of physical cash. If every bit of Cryptocurrency is traceable and track, it will make crime a lot harder to be worth while.
criminals are just as active with credit/debit cards and cryptocurrency and will always find ways around security measures (that's why it's a constant fight to improve security measures)