Bookmark Managers and Privacy/Security?

I see two types of app this entire discussion. One is just purely for bookmarks syncing, the biggest name being xBrowserSync for obvious reason, the other being the so-called ‘read-it-later’ apps, saving articles for later read, mainly for productivity use, like Omnivore(which is a very good alternative to Instapaper).

So for managing your bookmarks, I guess both works…?