Is it worth getting an Amazon pay icici credit card?

I have 4 credit cards right now, no icici card, good credit score (805 cibil). I am a frequent shopper on amazon and a prime member, so thinking of getting it, considering no joining/annual fee. Any downside of getting this or any better alternatives? Will this be applicable for icici credit cards discounts outside amazon as well? Asking this because I heard that there are cases where all ICICI cards are accepted, except this one.