Bitcoin has no intrinsic value.
I don't think you know what that word means.
The bitcoin protocol provides many things that we humans value, therefore it can be said that it has "intrinsic value" to humans.
Although, all value is subjective. In the end, if humans didn't exist, NOTHING would have value, therefore nothing actually has "intrinsic value".
So, regardless of which concept of "intrinsic" you want to use, your statement carries no meaning.
It's only valuable right now because people are willing to pay fiat for it.
You've got that one backward. People are only willing to pay fiat for it BECAUSE it is valuable. People don't pay FIAT for things that don't have value.
You'll find that many people are willing to exchange products or services in exchange for bitcoin. This will continue regardless of whether or not they are willing to exchange their local government currency for it.
If fiat goes to 0, so will bitcoin.
Which fiat? U.S. Dollar? Euro? Peso? Yen? Bolivar?
If one fiat currency collapses, and others don't, then wouldn't Bitcoin still have value in those other currencies? If it still has value in those other currencies, and the local currency does not, then can't it be used for international trade? If it can be used for international trade, then won't it be valuable to anyone that imports (or exports) products or services? If it is valuable to anyone that imports (or exports) products or services, then won't it be valuable to anyone that engages in any business with someone that imports (or exports) products or services? If it is valuable to anyone that engages in business with someone that imports (or exports) products or services, then won't it be valuable to anyone that engages in any business with that person? Doesn't this mean that it will carry value in the local community? Doesn't that mean that it will continue to carry value regardless of what happens to the local currency?