The currencies (Diem and XRP) would be similar in nature, since they're not mined but centrally issued, and their value is determined by a combination of factor

The currencies (Diem and XRP) would be similar in nature, since they're not mined but centrally issued, and their value is determined by a combination of factors (the issuance, decay, and trading). As far as I know Libra/Diem is more customer-facing, whereas Ripple is mostly marketed to banks for faster international transfers.