I've been working in startups for the past 10 years and I know at least 2 successful companies I worked for started out as spreadsheets and a lot of manual labor.
Do you know of any other companies that started out as spreadsheets?
Here are some others I can link of:
• ZeroCater (reference: https://techcrunch.com/2013/04/06/how-i-started-zerocater/)
• Credo (reference: https://www.entrepreneur.com/article/297611)