A license doesn't matter if the perpetrator doesn't comply with it.

Open source licence requires attribution which obviously it is not done in this case.

No it doesn’t? Depends on the license

I doubt that there is any open source license that don't require attribution but we are talking about a specific case and the license require it [1]

[1] https://huggingface.co/moonshotai/Kimi-K2.5/blob/main/LICENS...

Like licenses are worth anything in the AI world…