Whenever I hear things like this, I ask ‘What’s the problem they are actually trying to solve?’

Let me list some possible benefits. Presume a premined centralized currency like XRP.

1. You can impose a mining fee and control the exchanges (miners). This would impose a tiny tax on every exchange of money and you can reduce or eliminate other taxes.
2. Easy exchange and transfer of money to and from overseas.
3. Easy peer to peer payments.
4. Easy tracking of transactions to eliminate money laundering.