Uh, are you sure of what you are writing here? Time-frequency analysis (including spectrograms) is one of the very fundamental tools for signal processing.
True, i was thinking of a spectrogram as purely a visualization of a time-series of DFTs but Matlab and other tools do not make this distinction.
I was mainly responding to the OP's distinction between analyzing a visual representation and analyzing a "2d array" when they are basically the same thing.
> analyzing a visual representation and analyzing a "2d array" when they are basically the same thing.
This is what I mean. I guess their tooling just outputs graphics and it's easier to work with those than the pure 2d array in numpy or something similar.
I was mainly responding to the OP's distinction between analyzing a visual representation and analyzing a "2d array" when they are basically the same thing.