I am currently working hard on separating Intervals.icu from Strava. You can manually upload .fit files + automatic download from Garmin Connect will be live on Friday. Soon you won’t need a Strava account to use the platform.
Strava is no longer granting app rate limit increases which effectively caps the number of users an app using the Strava API can have.
Intervals.icu is currently quite cycling centric (I have a gammy knee, so no running for me!) but there is a lot of running stuff on the todo list that will get done eventually.