The conclusion to my excel analysis is that DCB offers far better reward rate (incl Global value Program, milestone benefits, memberships) and lounge benefit on international spends (3.25% net upto 1L/ per cycle and 2.25% net post 1L and unlimited lounge) without annual fees (5L spend waiver).
For domestic spends, rewards rates with DCB can be as high as 16.65 - 33.35% on flights, bus and stays and 10% on IRCTC, regular expense (by buying amazon GV). Hence I will try to increase my income and aim to get DCB in next 3-6 months.
I will keep my SBI Vistara prime for Rent, Utility, Fuel, Insurance, Jewellery, Govt bills for 4.25% returns (assuming free PE ticket value at 4000 Rs and CV value at 0.8 RS).
This way I hope to simplify my card portfolio to just 2 cards.