each of the platform has its own algorithm to push content. Youtube, either short videos or long videos, push towards searchable content. Where as Tiktok is tailors content based on users's engagements and interest. Stories are temporary content that are good for flash sales or instant offers. Reels are permanent content that can be used for branding and building long time sales.To all that, another thing I realized is that Instagram reels tend to be more friendly, YouTube shorts tend to be more educational, and TikTok videos tend to be more entertaining. They are slight differences that make a video for one social network very different from another.