I argue emojois make it easier to understand. Whether conveying sarcasm, frustration, joy or anger. It's much easier to infer the tone of a message using emojis.
I'd agree that for emotional context, it can be useful. But I don't think the way they are used there is easy to understand. I mean what's the meaning of the heart regarding CI or the pen for bugs? Is that indicative of a categorie of commit (CI, bug-fix...) or just to decorate the message?
Also another issue is that emojis are not as easily indexable/searchable.
Also another issue is that emojis are not as easily indexable/searchable.