In a move similar to reddit or twitter, Strava is restricting API usage, and other policy changes.
I think an alternative to strava, which is also federated, would be really cool
EDIT: I know you can record teacks and keep them offline and there is plenty of ways to do so. I think the main aspect of Strava is the possibility of sharing the activities with contacts on strava itself.
Like for peertube or pixelfed, the fediverse has the potential to allow any user to share what they like and the other users can see, boost, comment, from their mastodon, pleroma, froendica or wharever accounts. The fact that someone wants to share a track is his own business.