OK but does IT exist to serve the business by accepting responsibility for stuff that doesn’t meet their standards and they can’t really support? Why have qualified people at all then?
I can't speak to IT specifically, but generally the answer would be yes. Stuff happens, resulting in "nonstandard" or unexpected requests, and the decision on how to deal with them rests with the business, with reasonable input from the people involved. In my own work, this can often happen by accident when departments and business units are reorganized and acquired. I once got an entire product line dropped in my lap, that didn't work at all, hardware or software.
Many, if not most, professions are not nearly as well organized and optimized as IT, so we don't have things like silos and ticketing systems to regularize our work. I can imagine an IT worker who has never experienced a nonstandard request, but I can't imagine it in my own occupation.
If the business relies upon that Access app, and IT refuses to accept it, then it's a failure of IT to accept it and then replace it.
IT exists to serve the business.