I started using Strava years ago when Garmin connect went under a major redesign that I hated,
over time Garmin connect got better to the point where I don't even really look at Strava much anymore. I find stravas constantly asking me to start a "free" trial very annoying.
Garmin tracks mileage on my gear (and does it better than Strava now IMO)
Real miles vs zwift miles
Livetrack shares my location with family when I'm out riding
I do use the Strava heatmap to find places to exercise when I'm traveling, I probably shouldn't say that or they'll start charging for that too.....