Do you have usage stats for such tools? A while ago, share buttons were everywhere. A year or two ago, I looked in their effectiveness, and I vaguely remember that they were not used that often, especially since browsers allow sharing to apps.
In all seriousness, I think it's true that those buttons mostly are useful as reminders that you can post / share elsewhere. Which is another reason why moving on from the "share to Twitter" / "share to Facebook" paradigm from 2009 is probably a good idea. There's a whole open social web out there that people need to be encouraged to explore.