I think the best explanation and understanding I received about Fourier Transform was from studying linear algebra.

The Fourier Transform equation essentially maps a signal from the time domain onto orthogonal complex sinusoidal basis functions through projection.

And the article does not even mention this. =)

Best explanation I got was from 3 blue 1 brown! It’s what you said, but with nice visuals

Almost every paragraph of this article says the same thing but in different ways.