Maybe you can disconnect the mic & camera, but since most modern audio chips are programmable it's possible to 'listen' to the speakers (think about it: a speaker is sort of a microphone in reverse). When a nation-state level player decides to eavesdrop there are many possibilities a hardware disconnect won't fix (some involving not tampering with your laptop at all)
A hardware disconnect fixes no problems most users have that's not solved by having a mostly secure OS with clear indication of recording status, while introducing some friction (like having to search for the magic button to turn the camera on when needed).