Versioning is of course more difficult, though Excel does support diffing in principle. I expect though that what most people end up doing is simply keeping track of versions manually, same as they would have in the days before excel.
Unless the other computer is set to a different locale and your data contains formatted numbers and dates. Then everything breaks.
I’ve not really dug into the feature but it’s very visible on the latest builds.
The current enterprise network I'm on? They block Box, Dropbox, and a lot of other solutions. They instead use Citrix's ShareFile and a NAS setup with file naming.
Also remember, surprisingly most of these critical infrastructure planning isn't handled by hundreds of people, at most it's a team of 5 people who then present their findings and suggestions to the C-suite decision makers. It's not as big of a problem as many people think.