There are multiple definitions of security, but they are always dependent on a threat model.

Facebook measuring how much time you spend on a given post and building a profile of you based on that on their servers is not at all the same level of privacy concern as third parties having access to your location.

Also, linux phones give no way to defend against the former either way, and the latter is not a problem on android or ios phones.

Nonetheless, I apologize for the patronizing tone.