If two business processes interact through a spreadsheet, or more than two people edit, you're going to immediately run up against the rough edges. Multiple people editing the same sheet inevitably ends in error. It can take a really gross amount of time to update the data when you're pulling/pushing from two sources. It may seem small on the surface, but even 2 hours a week adds up to nearly 3 weeks of work over a year. Can you replace this spreadsheet in 3 weeks?
I've seen this play out many times at large and small scale. The first example that comes to mind is a 10-hour day trip my wife took to go out of town and manually update a whiteboard because somebody messed up the shared spreadsheet. She was very unhappy, and this wasted a precious day during a _very_ busy period. Initially, the whiteboard and spreadsheet worked great, so they didn't "fix" it. It didn't scale to the busy times and really screwed them over.
At a much smaller scale, I wrote a quick SQL query to get some business metrics for the CEO. He asked if I could run it for him every week. Since I didn't have a good place to put this query, I just ran it manually and emailed it to him at first. Then he wanted to share it with someone on the opposite coast outside our network, so he asked if I could start putting it in a shared spreadsheet. My initial thought was to bang out a page they could pull up instead, but I figured it wasn't worth it. Then he wanted another metric. And another that required a bit of logic that couldn't be done in SQL. Pretty soon I was spending an hour a week manually running SQL and copying the results in to a spreadsheet. (We're a Google Drive shop. No way to connect Sheets to DB2.) That's simply not worth my time. I should've listened to my first instinct.
The initial investment in a spreadsheet isn't large, but the ongoing maintenance can really rack up hours. I think it's very often worth investigating any spreadsheet that users have been maintaining/recreating for more than a quarter.