Don't know about laptops but on recent desktop motherboards the jack detection and output/input switching is done in software. Probably the case on many laptops too. So this approach shouldn't be considered a "hardware switch" as it's still possible to capture audio from another mic even when a headset is plugged in.

On both of my XPSs I can switch to internal or external mic regardless of a headset behind plugged in, so the snarky suggestion to use a cut-off headphone jack is misguided and won't work on many modern laptops.

Bold to assume I have a mic jack in 2021.