You issued the card. Someone else is getting the spend.
Competing for card spend on rewards and introductory rates is a fight won by whoever has the deepest pockets. It is expensive, it is copyable, and it never ends.
The real barrier is smaller and duller than that. Moving a dozen recurring charges to a new card is a chore, so consumers do not do it. The card sits in the wallet as a backup while the subscriptions keep running somewhere else.
A card that is not top of wallet loses relevance quietly, and then it loses the relationship.