Closing the actual physical Amex offices also was a big step down (I've been a member since 97).
I would not want to bet on Amex at this point -- losing Costco, competition from Chase, and now Citi pushing to expand their own cards.
I'm surprised there hasn't been a lower-merchant-fees challenger now that everyone has a mobile phone; you could probably do something which presents at POSes as a credit card, handles a bunch of auth back through the customer's own mobile phone connection (but encrypted/authenticated), presenting a time of use credential which is matched by the POS while appearing as a regular credit card. Building something like that which costs the merchant <1%, and maybe which provides customers with a lot more purchasing/receipt info (for company purchasing cards).
If Goldman Sachs (or Apple) offered a 5% return to purchases using Apply Pay, I'd use it.
If I could give out purchasing "cards" to all my team which relied on Apple Pay but brought back realtime stats, that'd be a win too (especially if it did things like track capital purchases, warranties, management, etc.)
It was still an okay experience but not what it used to be.