Look for coordination cost
The problem is not the spreadsheet. The problem is when decisions depend on copied data, hidden formulas, manual updates and one person who knows where everything lives.
Build the smallest owned system
Internal SaaS should start as a narrow workflow with clear users, permissions, data states and reports. A small owned system beats a large vague platform.
Keep exports, remove chaos
Good software does not trap the team. It standardizes the work, keeps history, reduces duplicate entry and still lets operators export what they need.