I used to attempt this often as well. Had a few minor wins, but typically I was met with polite indifference, told it was their department. Which is fortunately better than active sabotage.

One group was even bewildered I was able to integrate a department client app with their ticket database. Reduced necessary clicks by 95% or so. They didn't think it was possible. Yes, this is the caliber of folks working at a big corporation.