It's a totally useless metric for productivity but I think the adoption thing is something that should be tracked and used. I big corporates you have a lot of holdouts that will send Emails instead of using a shared Doc for the next 10 years if you don't somehow tell them to not do that.

And no question this has nothing to with productivity or an individuals impact on the company, but I think we here seriously underestimate ho slow some people are in using new available tools and I can see some value in that perspective.