Also > natively embedded into a message I don't think any chat platform ever does this because they would like to support low bandwidth clients but maybe I'm

Also > natively embedded into a message I don't think any chat platform ever does this because they would like to support low bandwidth clients but maybe I'm just making this up. Practically every service uses a separate file storage service and if not URLs they use some identifier to reference them within said service. I think maybe you're referring to email, but even then, most MTAs and MUAs will strip embedded multimedia from the body to be downloaded separately anyways (at the user's behest), for similar reasons, but also privacy reasons (and security reasons).