When the circuitry is handling information (analog or digital), current needs are low. High impedance is okay. If you're careful you'll avoid loading the previous stage. Excessive loading causes distortion of the information.
On the other hand, to do work it takes current. Meaning watts. You must generate power, and you want to convey it most efficiently. Components that can do this need to have low minimum resistance, and to be robust. These tend to cost more, in contrast to small signal devices.
Examples of low current, high impedance circuits:
audio preamps
oscillators
sensor input
etc.
Examples where you want low impedance (emphasis on current transfer):
output stage to audio speakers
final rf transmitter stage
solar panels
battery charger final output stage
etc.