Spectroscopy is powerful.

There are various forms of spectroscopy that leverage different physical characteristics: vibration, absorbance, emission, charge, etc.

It's spectroscopy that allows us to read the molecular atmospheric composition of exoplanets and that has the greatest chance of yielding detection of alien biosignatures or technosignatures given our current scientific understanding and capability.

Spectroscopic techniques are vital for remote sensing, cancer detection, biochemistry, materials science, and more.