A significant amount of ML work is done in Excel with more on the way. For example, see the book "Data Smart: Using Data Science to Transform Information into I

A significant amount of ML work is done in Excel with more on the way. For example, see the book "Data Smart: Using Data Science to Transform Information into Insight" by John W. Foreman. There oughtta be a "law" about this; something like "Every software system eventually has an Excel implementation" or such.