IDFC First Wealth is perhaps the most remarkable card in India: it's lifetime free yet offers premium card benefits including 4 airport lounge visits per year, 6X reward points on dining and travel, and even UPI rewards. No other free card in India offers this combination of benefits.
Called "the best kept secret in Indian credit cards" repeatedly on r/CreditCardsIndia. The combination of zero fee + lounge + UPI rewards generates disbelief. IDFC First Bank's customer service is praised as better than HDFC. Main concern: bank is smaller and less established.