Why can’t I insert the Football Emojis directly into the text when writing a message?

Only so called unicode emojis can be inserted directly into the text, and it is only the OS developer (Apple, Google) who can manufacture and control those. For now no third party developer can create and handle unicode emojis. As a workaround some developers create their own messaging apps to be able to insert their own emoji stickers directly into the text, but then the receiver have to have those apps installed as well. If Apple allow sticker-emojis to be inserted directly into the message text in the future, we will update Football Emojis with that feature.