DCB has 3 aces up its sleeve that Infinia does not -
1) Milestone vouchers worth 1k (I go for 2x250 OLA + 500 BMS) on 80k spends in a calendar month
2) 2X RPs on weekend (Sat-Sun) dining at standalone restaurants (no Swiggy, Zomato etc)
3) You got DCB LTF. For people with paid DCB, the annual fees are waived for spends of 5L v/s 8L for Infinia (plastic) and 10L for Infinia (Metal).
Obviously, Infinia's big ace is double the RP limit on SmartBuy (15k v/s 7.5k) and higher RPs (5x v/s 3X) on Gyftr vouchers. Better acceptance (DCB works in 9 out of 10 places where Infinia does) and no 2.5-3.5% fuel surcharge are also added advantages.
Both cards are excellent and which card suits whom is subjective.