Except that the moment you "share them across devices", at least one large company will silently grab your contacts anyway. And several others will try to, too, with one excuse or another.
So though you have a point, I don't think it goes against the post.
I want to have multiple devices able to access my important data.
I have no interest in sharing that data with Google, Apple, Facebook, LinkedIn, or $SMALL_TIME_APP_DEVELOPER and will actively avoid any system that requires me to do so.
It's essentially file share for database records, and I remain surprised that something like this isn't in wide use already.
Docs haven't been updated in years, but here's a description of the thing back when I was focused on the client rather than the sync engine -
https://www.wittenburg.co.uk/Entry.aspx?id=a7aae391-9ac8-411...
Whatever you're using to sync contacts, without syncing them to this contact app, it seems (to me) as useful as keeping a textfile full of phone numbers in Dropbox. You won't have any useful prompts telling you that it's Dave phoning you, John texting you, or Alice's number to phone/text.
This is, admittedly, neatly worked around by keeping your permission requests under control, but... stuff like this[1], from before the granular permission system on Android was available, are annoying.
1: http://bgr.com/2011/08/12/facebook-stole-every-contact-and-p...
But that wasn't the article's concern at all, as you pointed out in another comment.