As far as I know, many people prefer to upload photos and videos to third party resources in order to reduce the load on the Lemmy instance.
In addition, many instance do not allow uploading videos and you have to find a place where you can upload a video so that a third-party service can provide a direct link to the file.
Regarding video support in your app. Check your firewall. If reddit domains are blocked, you need to allow them. In case your app does not play videos from any sources - write about it to the developer of the app github.com/laurencedawson/sync-for-lemmy/issues
I’ve opened a bug report, hopefully this can be resolved.
Sync seems to implement custom handling for Reddit’s video domain (it needs to) and it’s constructing a bad URL in the process.
Agree on the last part (although these links are usually just Reddit reposts so I doubt they’ll be reuploaded anywhere), but we’ll need a different video host unless we stick to the potato quality links like the one OP posted.
Thank you for the report, I hope it gets resolved. I don’t mind having to click out for the time being. I unfortunately have no alternative for video hosting, but that’s a good one