I work in corporate finance and these issues are certainly present. However, they are almost always known and determined low priority to have a better process built. Finance processes are nearly always a non priority as a pure cost center/overhead there’s not many companies that want to invest in improving the situation, they’ll limp along with minimal investment even once big and profitable.

That said, every finance function is different and it may be unknown to them that you’re being asked for some data multiple times. If you’re enduring this process, I’m of the opinion you’re equally at fault. Suggest a solution that will be easier on you. As it’s possible they don’t even know it’s happening. In the case provided, email to all relevant finance people “Here’s a link to a shared workbook. I’ll drop the numbers here monthly, please save the link and get the data directly from that file. Thanks!” Problem solved. Until you don’t follow through which is what causes most finance people to be constantly asking for data/things. So be kind and also set yourself a monthly recurring reminder on your calendar and actually follow through.

And they've all been burned by enterprise finance products which were sold to solve exactly that problem.

Only different companies were all sold different enterprise finance products, but they need to communicate with each other (or themselves after mergers), so it all gets manually copied into Excel and emailed around each month.

I’ve just set the finance people up with read only access to our data source, and they now can poke through it themselves.