Is There a Shift From Geometry to Algebraic Expression?

In ancient Athens, Plato famously wrote over the doorway that was the entrance to the academy, let no one ignorant of geometry enter here. Simone Vay says we are now using symbols or signs on a piece of paper to represent something that doesn't actually exist in reality. If you're just solving a math puzzle because it's a fun intellectual exercise, reality doesn't really matter there either.