If you're a Garmin device user, the app is pretty good! I only recently started using their app more often and barring the social aspects, I dont think Strava offers me anything more. HR zones, recovery etc are all already in the Garmin app whereas its paid on Strava.

I guess for those who want routes/segments might gravitate towards Strava but I use a fairly standard set of routes so I dont value in that either.