One of the things I like about discord is you can set it to display the key you have bound for baritem on the item itself...
I have three bars I use with keybindings: 1-12, shift+1-12, ctrl+1-12, and while I obviosuly know the frequently used ones by heart, when I want to use another one without clicking, it's nice to know the hotkey instantly without having to risk pressing the wrong key...