@x42 I never saw such thing and honestly have no idea what that is about.
What "contact list"? email is kept separate, so not that... sms and phone calls are not on the smartphone, so there is nothing to read from there...

do people really keep a centralized list of all their contacts?

I have people scattered around:
- IRC
- telegram
- signal
- line (korean chat app thing)
- sms/calls
- email threads
- nextcloud chat

very few are in more than 1