The 2 problems with after pay are - you can only use it once at a time, pay off then bug again, and the $400 limit on the purchase, puts a load of items out of contention.
The merchant doesnt need to accept the 5-6% funding fee, if they just agree to receive installments.
It's not as if 100% of all purchases made are now going to be splitit.
retailers will evolve or dissolve