The last thing (I hope) standing in the way of Intervals.icu having full Garmin Connect support (seamless like Strava and no Strava account needed) is what to do about duplicate activities for people with history in both services.
My own setup is very simple: All my activities are on Garmin connect and go from there to Strava, so “keep Garmin Connect” activity and delete the Strava one will work. For old activities I should be able to move power and interval edits, chat and so on from the Strava activity to the Garmin one.
GC activities don’t have segments but I can live without those. Would rather not have all my data on Intervals.icu at the mercy of Strava.
Is there any use-case for keeping the Strava activity instead of the Garmin one?