1 column, 2 columns, infinite columns.
There are all kinds of use cases for infinite columns. All related to the ability to see and/or navigate to more information.
First one that comes to mind is Kanban. The use cases for more than two Kanban columns, you could find the same kind of uses cases for more than two columns in TiddlyWiki. All about visual organization and navigation.
Same reasoning when you look at Ted Nelson’s Xanadu.
Same reasoning as why anybody would need more than two columns in a spreadsheet.
A use case: a column of current events and how they related to events of 50 years ago in a second column, and to 50 years before that in a third column, and so on and so forth.