Banks are much less technological than the common stereotype about them. In fact, integrating or automating a bank is one of the worst things you can do. The list of easy integration goes like this:

  High-tech internet services
  Stock exchanges
  Websites with no API
  …
  Telcos
  …
  …
  Banks
  Unreachable rock bottom of insanity

You should see what the major players (especially MS) do to iCalendar. The standard has been around since at least 2009, with the last update in 2016, but none of the major players implements the standard correctly, and most utterly fail on VTODO, I suspect on purpose because to-do lists are actually useful.

I can't decide whether the failure to implement iCalendar and OFX standards properly are examples of incompetence or malice, but I suspect the latter with an eye to vendor or bank lock-in.