Spreadsheets are flexible and familiar. They break when five people need write access, formulas disagree, and nobody knows which tab is canonical.
Signals it is time to move
You reconcile the same channel twice because exports do not match. Reorder decisions wait on someone updating a master sheet. Finance asks for stock proof and ops sends three files.
What to keep from the spreadsheet era
Clear ownership, simple definitions (what counts as available), and a weekly rhythm. Software should enforce those habits, not replace them with dashboards nobody opens.