Specifically, I am curious why the control loop must be broken such that one side of the break is high impedance while the other side is low impedance and if this applies to more than just power electronics. I've read several app notes including TIs AN-1889 (Step 1: Setting up the Circuit, paragraph1) linked below. They all mention this fact, but do not explain why. Since the reasoning is not obvious, can someone explain the reasoning to me or at least point me in the right direction?
https://www.ti.com/lit/an/snva364a/...63681&ref_url=https%3A%2F%2Fwww.google.com%2F
https://www.ti.com/lit/an/snva364a/...63681&ref_url=https%3A%2F%2Fwww.google.com%2F