Ferinex wrote:- Inline image and gif sharing (this is a big one)
- Link previewing
- Server-pushed scrollback, including parts you were offline for (no need for keeping your own logs)
- User friendly
- Used by actual human beings
IRC client Mibbit had these things since way before Discord existed.
Ferinex wrote:- Free server hosting (arguably you can find free IRC servers)
IRC has a bazillion free servers you can freely create channels on (including the option to lock others out in multiple ways).
Ferinex wrote:- Friend list
Unnecessary on IRC. You can contact and see the status of anyone on the same server, provided you know their nickname.
Ferinex wrote:- In-client powerful search feature
Are you serious? Discord's search is terrible and sure as hell can't compare to text file search tools.
Ferinex wrote:- Avatars
- Emojis/emotes
- Voice chat, as mentioned
- 1 on 1 video calling
There are things IRC indeed does not have. Voice and video chat are outside of its scope as it's a text chat client, I've seen clients try the other two but I don't know if there are any actually notable clients implementing those.