In addition to other responses (particularly location data): VPN or Tor usage from a desktop is, for now at least, more viable from desktop than mobile.
Desktops can also have camera(s) and / or mics disable more readily than phones.
If the phone is powered on it allows for (potential) pervasive location tracking. Your communications can be listened to whether mobile or a home computer, but all that using your home computer reveals (by using it, not the contents) is that you're home. Using your mobile reveals that you're at Starbucks or on I-40 stuck in traffic, or that you're frequently connected to the same tower as some other persons of interest. And that's what can be known before observing the actual contents of the communication.