There are several issues with Strava and data. Their API doesn’t give out the original files so only data they chose to extract is available. The API agreement also says that I have to delete everything on their instruction and if a user revokes Intervals.icu Strava access. Also they are no longer bumping up rate limits no matter how many Strava users an integration has. That is a very big problem for a tool like Intervals.icu.
Some platforms are open (Garmin, Polar) so I can build integrations. Others are not (Zwift, Wahoo) which is unfortunate.
I could support uploading activities via a URL instead of just uploading files. That would make it a little easier but not as good as proper integration.