emmadilemma quoted Pegasus by Laurent Richard
NSO’s Pegasus system has not been limited to catching bad guys. It’s also been used …
That enormous client base [of 200m] was what made Truecaller the best and most comprehensive phone directory, because whenever a mobile phone user downloaded its app, Truecaller automatically scraped the entire contents of the new user's contacts file and added it to the database.
— Pegasus by Laurent Richard, Sandrine Rigaud (30%)
Any app with both contacts and network permissions can do this. Many don't say they do, and some say they don't, but you have only their word.