Because the state can create more currency, change interest rates and various other things that cannot be done with Bitcoin. This is by design and is widely celebrated by the community.

I'm surprised you don't know this.

You arent answering the question. Who backs the state?

The question is irrelevant, there is a clear difference between the 'backing' of a state which can manipulate the currency supply directly and the backing of entities that cannot.

You claimed that bitcoin's backers have the same power as the state. They do not. End of story.

No I claimed that they have the same function. Neither of them can secure against defaulting completely but the function is the same. There is enough inertia in the bitcoin network enough people with most of the bitcoins gotten at a very low price and holding, other words there is a base.

So no it's not irrelevant it's the very core of this discussion.