It matters a lot. The Blockchain (or rather the many different blockchains to come) are the ledgers by which transactions will be tracked in the near- and certainly the far-future.
It also shrinks the footprint of money down to your mobile device, which means that ATMs and even cards become uncecessary in many cases. Thieves who make a living stealing cash from banks will find no cash to steal.
However, this does not mean that theft will vanish. It will sinply go online. The Blockchain adds an extra security layer to the process and is better than what we have but it's pretty much impossible to stop malicious hackers completley.
As we evolove in this space, of course, we will becoem more sphisitcated in how we deal with these issues.