[nonbirithm]

It's a social problem rather than a technical one at this point. When Github had no emojis people had no choice but to leave '+1' comments. Now even with that choice some communities still comment in this way for some reason. Commenting is open-ended and moderation would be needed to filter out the repetition. People can also post GIFs, but they can also use the same image upload functionality to post screenshots of bug repros. It hinges on what the user believes is the better choice for getting the point across.

About all you can do is change the mindset of the community making the comments, which is hard as they're numerous.