A recent article in the AFR talks to what APT (soon to be SQ) has done to the banks.
Essentially, despite it losing money, fintechs like APT have forced the banks to modernise not just their offerings, but also their tech stacks.
I think APT (and SQ when it lists) will be a fintech force to be reckoned with and the big4 performance will continue to erode.
Disc: APT held in RL.