Originally Posted by
travelling companion
.... they literally only sell groceries. ....
It appears this was not always true:
Shipt is an Internet-based delivery service. In December 2017 it was announced that Target Corporation was acquiring Shipt for $550 million and that it would operate as an independent subsidiary following the acquisition. As of 2018, Shipt delivers groceries, home products and select electronics.
Read more:
https://en.wikipedia.org/wiki/Shipt
Do you still offer deliveries from restaurants or retailers?
Sadly, we do not. We only offer grocery and alcohol delivery at this time.
I would not assume that any change in their relationship with American Express is related to a specific credit card. It's more likely related to their ownership and the fees that they pay for credit card processing.