What are the advantages of piezoelectric microphones? And are there any drawbacks compared to dynamic and capacitor mics?

I know that it has a high impedance.

Which of these inputs is needed?

 

I worked with audio for 47 years and have never seen a peizo microphone.
Pros use dynamic, condenser or ribbon mics and toys and consumer products use electret mics.
A "crystal" mic might be the same as a piezo mic and was used long ago with tube amplifiers. I had a crystal mic 50 years ago.

Most piezo transducers have many sharp resonances and nulls in their frequency response.

 

They're waterproof and pressure tolerant, so they get used by marine biologists.

And yes, the auld crystal mics for the auld high-input-impedance tube amps were indeed piezoelectric.

 

So were the crystal phono pickups that ruined many a 45. They didn't even need a special preamp.