Which is extremely practical for French, where the colon comes after a space. So if you want to write an actual colon to introduce a list on the following line, you’ll just input whatever the default smiley is.
IMHO they are not. Using the shortcodes via () works okay-ish, but open the emoji menu is just awfully slow, it takes a solid 5-8 secs for it to show the emojis not recently used. It's absolute garbage.