For training, sure, but a significant proportion of Olympic calibre athletes use the social elements of these tools.
At least in road and trail running, this doesn't line up with my observation. There are plenty of elite athletes, at least in the US, who are posting their training on Strava (Jim Walmsley, CJ Albertson, Molly Seidel, etc.) At the fast amateur level (e.g. those chasing the Olympic Trials Qualifier time), Strava adoption is pretty ubiquitous.
Out of the the athletes who are active on social media in the first place, those who don't post on Strava are usually doing it either for privacy reasons, or because they do not want to share their training plans for their competitors to copy.
Yup, (personal) brand awareness. Strava is for casuals but the training results will be posted there regardless who you are (except as you mentioned, for privacy). As I stated above: Strava is for casuals, those Amateur->Pro level posted there "just because" it's easy to do it not because they rely Strava for Data Analysis.
Those athletes will rely on other platforms to analyze their training data (Garmin offers more insight for example).
Setting up Strava to link with Garmin is easy right? Things will sync from that point onward.
Always has been that way; that's the whole idea of Strava (or Komoot, RideWithGPS, etc). These platforms are for casuals.
> Ironically some of the highest performing endurance athletes I know don't even use it anymore. TrainingPeaks + Garmin is where it's
Always been this way as well (TrainingPeaks/TrainerRoads). These platforms are for training and improving performance. Garmin is Garmin... majority of endurance athletes wear Garmin devices (or Suntoo).
Having said that, it's easy to upload to multiple platforms so they all treat Strava or other social media as brand awareness.