One can be tempted to like any assault on "Uncle Bob"'s insulting videos in the light of working on a codebase where every 2nd line forces you to jump somewhere else to understand what it does. That sort of thing generates a rebellious feeling.

OTOH the class design lets someone come and add their new shape without needing to change the original code - so it could be part of a library that can be extended and the individual is only concerned about the complexity of the piece they're adding rather than the whole thing.

That lets lots of people work on adding shapes simultaneously without having to work on the same source files.

If you don't need this then what would be the point of doing it? Only fear that you might need it later. That's the whole problem with designing things - you don't always know what future will require.