I was surprised with the exclusive Costco deal, and less surprised that it finally ended.
AMEX initially started based on customer service to the wealthy. They are still very good to their cardholders, but everyone else has either closed the gap dramatically, or surpassed them. I haven't seen much improvement on the vendor side. As a user of their cards for corporate travel, their @home format sucks big dogs.
When they started, there were very few cards and the wealthy carried them. Now, they give credit cards to anyone with a job...and maybe even a lower standard than that.
It looks like AMEX made a major strategic blunder by fighting the anti-trust lawsuit. Time will tell. It also appears that Costco called their bluff, perhaps given AMEX's general approach to vendors. IMO, they really needed Costco to maintain their brand's relevance.
For me personally, I have had an AMEX card since high school - almost 40 years. Now that you don't need it for Costco and now that Delta miles don't expire, I am probably going to stop using the card entirely. They are a helpful way to help your kid get credit, or so it seems. Helped me when my dad gave me mine in high school in anticipation of going to college. I thought it was pretty cool that I had a "gold card" back then...
My long term expectation for AMEX is a lot of struggles.