Linux PinePhone has physical kill switches for its cameras, mic, data, BT, Wi-Fi
Off-topic but IMHO what is really needed these days is a privacy feature allowing all the UIDs to be changed freely by the user (without the need for rooting and firmware thinkering).Including randomized IMEIs and randomized Android ID (In addition to the already offered randomized MAC and Ad tracking ID changes). 
Especially IMEIs which are commonly used by many applications and law enforcement to track users (see Banking apps for instance that all require your phone permissions to read such IDs).Nor Librem nor Pinephone offer this functionality from what I know.And no, it's not (yet) illegal (but might be against some ToS) in many countries to change your IMEI including the US (see https://en.wikipedia.org/wiki/International_Mobile_Equipment...).