I am a student, Amazon prime member and order from Amazon pantry every month (for 2 families). I am quite a heavy user on Amazon. Applied as self employed with 3.5 L ITR and was rejected after 15 days.
if you have a better card (more than 1% cashback or points) for regular expenses. use that. Amazon is mostly good for amazon purchases only. and if you still use Grofers. i suggest trying to get the stanchart digismart card. digismart card saves me more on grofers than amazon card does on all non-grofers spendings (i easily save 1000 bucks on grofers alone in a month). i also end up making one purchase a month on myntra to use their offer. it also has benefits on zomato, ola and one other platform.