I can't be the only one who uses additional apps to track various fitness and health aspects. It would simplify things if Connect would sync activity and even step data to Google Fit. This would provide a single pane of glass for an overall view, the detailed data would still live in Connect.
There are a number of threads about this. Within those threads are different ways to link to Google Fit. Some involved a lot of steps but apparently did work. Others used a third party like runtastic pro as an intermediate step. Try searching for Google. You'll get 34 pages of results but you will find some good info.
I maybe wrong but I think apart from myfitnesspal, the other apps PULL the data from Garmin; Garmin does not SEND data to 3rd parties.
Maybe contact Google and ask them to provide the means to pull the data from Garmin like Strava and SportTracks.mobi do. Failing that contact the people at https://tapiriik.com and see if they'll provide a mechanism.
Garmin doesn't really have an incentive to do so. It's unfortunate to see so many walled gardens. But at least in this case there are ways like with Strava to sync activities to Google Fit after you sync from Garmin. I've complained about this before with Garmin, and I used to work there! ;-)
And this is not Garmin supposed to match Google Fit? When I run an application that can synchronize data with Google Fit, it asks whether to provide data for Google.
It's Garmin who needs to add the option to send data to a Google Fit account.