Is the Amazon credit card worth it for me?

My current cards:

- Venture X, Savor, WF Autograph, Quicksilver, Discover IT

I spend a lot on Amazon... too much honestly. So despite my other cards probably earning better for me in terms of % and need (eg, I travel alot so Venture X is my main card).. I feel like I'm leaving money on the table here? So is it worth adding this card for me, or should I just stick to the current line up? I know it's free so i technically have nothing to lose, but I also don't wanna take away points/miles earnings that may be more fruitful.

Also... do I need to have a Prime account in my name to open the card? Or is it fine if i share a Prime with someone else?