Every Connect IQ app seems to need to use GCM to do anything. Strava Routes as an example. If I have WiFi, why can't you just use that? I've already authenticated, so use the better connection? Same with other apps that seem to HAVE to use GCM
I believe it comes down to battery usage which is very high for wifi. Therefore, Garmin have chosen not to allow wifi for anything other than syncing. The music devices allow syncing music via wifi, but this is only possible when the watch is connected to an external power source.
Edit: Just to clarify, music is only synced via wifi for the music apps such as iHeartRadio
One small correction to what gasteropod says here is that it appears that the Fenix 5 Plus series allows you to sync without being connected to an external power source. This is likely due to the larger capacity on these device compared to most Forerunner series devices. I realize this is not the heart of this thread, but want to make sure there isn't any accidental misinformation.
