Which of the following would be reasons why would want to use "untidy" data:

Choice $1$ of $4$:Plotting multiple variables in the same way

Choice $2$ of $4$:Using the most common formats for exchanging data

Choice $3$ of $4$:Applying functions like group$\_$by to group the data by variable, rather than by unit

Choice $4$ of $4$:Efficiently store data with many missing values or many duplicated values