Honestly I've been wondering if in the near future I can basically have a big machine and some sort of "ingest" program.
Then keep connect my devices to it, where it will backup all the data, and mine the backups for information I want.
Mine my iphone backups for text messages or contacts
mine all my devices for photos or videos
mine my watch or bike computer or gps or whatever else for where I've been and how I've exercised.
instead, everyone wants your data and imposes themselves in the middle.
Strava (and I assume to some extent Garmin) apply some smoothing to these raw GPX traces to try and improve the path, or remove some of the noise.
You'd be missing out on this post-processing by taking the data raw. Ofc you can implement something similar yourself, but I wanted to point out that these platforms are doing a little bit more than just displaying the GPX trace.