Apple states that every feedback submission is read by them but they will not respond back.
Now for some history.
First, Goldman Sachs Bank has always been a corporate investment bank. Until the release of the Apple Card they had NEVER touched the consumer credit market. So your quip about not playing well with financial software is a bit out of place. They don’t play well at all.
Second, since the introduction of the Apple Card users have been grousing and upset that it does not connect to financial software like Quicken or other packages like you mention. It’s likely thousands of Feedbacks have been sent already demanding a change. Two years on there’s no change. It is now clearly apparent that Apple/Goldman Sachs has no intention of allowing such connections.
So either live with it or cancel your Apple Card in protest. You’re a bit late to the protesting as this has been going on for years now by other users, myself included. I have chosen to live with it.