I had for several years a AMEX platinum. (I did it for airport club access and other perks that, at the time were worth the yearly fee.) During those years I purchased an item with a lifetime warranty, upgraded to that because of the card but handled by the seller.

Years later, after I had traded in the platinum card for an AMEX blue card, I needed to take up the merchant on the warranty. I called expected a big hassle. The merchant provided an address to send the item, which I did with some trepidation. I fully expected a phone call or letter stating in effect no card no service. In stead after ~2 weeks I got a phone call from AMEX. The merchant had contacted them about the warranty the REOPENED my Platnium card to credit the full purchase price and were calling to find out what I wanted to do with the balance. In 5 min. the credit was transferred to my AMEX Blue and the platinum account closed again.

I to have had fraudulent charges flagged very quickly by AMEX.

And I use only that credit company. If a merchant does not take AMEX I avoid it when I can and use my bank card as a VISA when I can't.