The first thing that came to mind was governmental expenses. Of course it would by far help in the elimination of corruption as every transaction would be open enough for the world to see.
But...
I now thought again. Cryptos are limited in number. And the magnitude of government expenses and funds may just mean that five or ten countries would swallow up the whole cryptos available. So be it wouldn't work all that easily in practice.
Yes, there are many sectors that it would be seamlessly brought into but, I'm one of those with a rather old soul. I still like the feeling of raw cash/fiat in my hands.