A lot of software (Github, Okta, etc. etc.) will just delete portions of their UI, usually because you don't have permission to access it, or even just some of it. So, if you google "how do I do X?" the AI — assuming it gets it right at all — will tell you to click on UI that doesn't exist. Even if you then scroll to the organic docs, those will also have you click UI that does not exist.
A greyed-out item gives you the affordance of knowing that that feature / path exists, even if it's not available right here, right now. Truly good UI would also give me an affordance of knowing why (e.g., a tooltip saying "to access blah, you need permission blah"), but that's just asking for the moon, I know.
But when you're staring at docs referencing a non-existence menu item: is it because I lack a permission? What permission? Or perhaps the docs are just out of date? — you don't know!