Here’s how I think about it, in much looser terms:

unknown = I don’t know

any = I don’t care

Often the implications are the same, but as you can intuit, any is a lot more relaxed.

Any will work anywhere because you just don’t care what the type is.

Unknown is stricter. It won’t work in cases where other types expect you to know what type you’re dealing with.

The compiler treats unknown very cautiously, whereas you can slap an any on pretty much anything.

Consider a ‘dump’ function. By design, it handles anything you throw at it - strings, objects, booleans, etc. It won’t change. That’s ‘Any’.

Whereas ‘Unknown’ might be a stepping stone to introduce a more specific type once all the use cases are known. I let it handle strings and integers, log a line about any other type that calls it, and continue behaviour as it is today.

They're the same as much as "1 + 1 = 2" and "2 + 0 = 2" is the same. The result might be the same ("any" and "unknown" accepting any type) but again, the intent is different (a value we know can be anything vs a value we don't know what type it'll have).