Is that really true? I figured they all (phones and computers) were tracking everything.
There a limit to everything. I try to keep google off of my mobile devices as much as possible as their ads track you, your searches track you, and their mail system tracks you. . . and YouTube tracks you. I only goto fakebook on my home Mac in a protected partition to see pics of my Granddaughter. I never had a Twitter account. . . and when I go there to see something for Q, it's in a sandboxed partition.
Everything about Apple is sandboxed and secure. Apple does NOT have access to your data, even on iCloud. Your uploaded iCloud data is encrypted. It is split into four discrete pieces, each of which is stored in four different locations, each encrypted by Apple to a 256 bit Advanced Encryption Standard (AES) standard. It can only be put back together when you recall your data. What you store on iCloud is by your choice. Everything on your iPhone or iPad is ALSO encrypted to a 256 bit a, stronger than most financial security, which uses a password that would require 5.62 X 10195 years to crack using brute force guessing, which right now is the only way to hack into a 256 bit AES encryption, using the fastest supercomputer on the planet. You've probably heard about the police having a GrayBox that can crack even the most modern iPhone, but that merely hacks the device's passcode. . . but If you merely change your passcode to a seven character alphanumeric complex passcode, even that GreyBox would require 46 years to crack that. . .
Keep in mind that Apple does not have your passcode and It is NOT stored on your device. . . so don't forget it.
On the other hand, anything you do that LEAVES the device and goes through an Internet carrier is no longer yours. They can see it. Anyone can see it. It is essentially fair game for anyone to try and grab ahold of it and try to decipher it. Legal? Probably not. . . but you must assume they will try. That even includes the very minute radio waves that the screen gives off as you press virtual keys on the virtual keyboard. If someone is close enough with a sensitive enough device, they may be able to pickup and interpret those radio wave and determine your passcode. Unlikely, but entirely possible. Accurate? Probably not. However it's been done in locked rooms with two computers.