When I joined my current team, I was surprised when I realized all of my co-workers were using the end of strings to verify their identity, when I was looking at the beginning of them. It was confusing: I'd be reading off random characters, and they'd be reading them aloud at the same time, and we'd all be saying different things.

I've run into this with GUID/UUID strings. Some apps truncate them while appending an ellipses to the end, so that the last bits of characters are not even visible by default. It's a mixed bag to be sure

I feel like if you have to display UUIDs in your app’s UI, you’ve already lost. Copy to clipboard should hopefully be enough.

It doesn't matter when/where the IDs are or how they are to be used. Ever been on a call trying to get someone to look at a specific commit? There are plenty of cases where using some sort of ID is necessary. I think you've chosen the very wrong part of the comment to focus on, like the actual point.