I've noticed that emoji and stickers are absolutely not used in the same way.

People often combine multiple emoji to express certain things that can't be expressed with a single emoji (and too difficult to find/create a sticker for).

Stickers are also much less subtle and more in your face, and therefore not appreciated in the same way.

although i’ve noticed mostly human emojis can be used consciously. the others (tree, objects, etc) are suggested when you type a word but almost never selected to replace words in a sentence. So i don’t know who really uses them.

Not full sentences perhaps but there is a reason the Egyptians used hieroglyphics, and a reason we say a picture is worth a thousand words, so adding some to a text message is very common

I had to make my girlfriend stop doing that because I couldn't decipher what she was saying, it was like +30% extra information I thought was decoration :D

Also, on Tinder bios emoji soup is a thing.

Almost no one, besides some country with the biggest population on earth. ;-)

Btw:

http://www.emojidick.com/