Not sure. Still learning
Discussion
More mints might have some advantages, not far from reasons why people hold accounts with more than one bank.
Ecash wallets like #minibits allow you to spread the trust in funds custody across more then one mint: typical custodial lightning wallets don't provide that.
In the longer term if ecash takes off, mints might differentiate by other features like providing ecash representing other assets like USD or having good lightning connectivity in specific regions thus providing reliable pay-ins and -outs etc.
We are very early.