Why variable capacitor doesn't use to position sensor?

Hello, I saw a video about PCB motors on YouTube.

Yes, it looks like a BLDC motor to me.

It seems difficult to attach a position sensor like a magnetic encoder to such a small motor. However, I was thinking of one last option: what about using a variable capacitor?

Structurally, a capacitor is simply two sheets of metal placed close together.

The capacitance changes depending on the overlapping area of ​​the two plates due to rotation, and this can be detected.

However, I’ve heard online that capacitance is susceptible to noise but, it can be manufactured like a PCB.

I don’t want to dismiss this possibility.

As long as it’s shielded properly, will there be no noise? In your opinion, how likely is it that a variable capacitor could be used in a motor like this?