If you’re unlucky it’s your only integration tool. When there are no APIs, when you can’t get approval to use a tool or language, when the DBAs won’t return your calls; then export to Excel is the only integration tool you’ve got.
A few years back I remember a big corp explicitly telling me that a project for an Excel based integration between some systems would have easily got buyin and budget. Despite it being in a broader sense a crappy tool for the job due to everyone having excel installed and almost nobody being able to get approval in a reasonable amount of time for anything else to get installed it did appear to be the easiest option in the circumstances. Before this I think I was one of those people who just ruled out using Excel for integrations because I just couldn't see how it could possibly be the best option in any circumstances.