I've had the card for around three years now, and never had an issue using it anywhere.
I have a feeling that there is some missing info on some of these reviews that people leave. I was reading a one star review the other day about an unrelated card where the reviewer was angry because her new card was declined when purchasing a couple hundred dollars in gift cards. I can absolutely see that happening, and it makes perfect sense. I wonder how many other bad reviews also have details like this left out.
I stopped using Chase cards for a while because of fraud alerts. I had fraud alert twice while in the same store. I even called after the first one, but it happened again within minutes
So, that's not Amazon card things, it's overzealous fraud dept thing for some people. Others have no problems at all
It has stopped even for me, so if that card fits your spending, dont worry about Amazon reviews.