We don't have to match the quantum state since the brain still produces an valid output regardless of what each random quantum probability ended up as. And we can include random entropy in a LLM too.

This is just non-determinism. Not only can't your simulation reproduce the exact output, but neither can your brain reproduce its own previous state. This doesn't mean it's a fundamentally different system.

>Consider for example Orch OR theory

Yes, or what about leprechauns?

the transition probability matrices don't obey the laws of statistics?

>If we don't think the candle in a simulated universe is a "real candle", why do we consider the intelligence in a simulated universe possibly "real intelligence"?

I can smell a "real" candle, a "real" candle can burn my hand. The term real here is just picking out a conceptual schema where its objects can feature as relata of the same laws, like a causal compatibility class defined by a shared causal scope. But this isn't unique to the question of real vs simulated. There are causal scopes all over the place. Subatomic particles are a scope. I, as a particular collection of atoms, am not causally compatible with individual electrons and neutrons. Different conceptual levels have their own causal scopes and their own laws (derivative of more fundamental laws) that determine how these aggregates behave. Real (as distinct from simulated) just identifies causal scopes that are derivative of our privileged scope.

Consciousness is not like the candle because everyone's consciousness is its own unique causal scope. There are psychological laws that determine how we process and respond to information. But each of our minds are causally isolated from one another. We can only know of each other's consciousness by judging behavior. There's nothing privileged about a biological substrate when it comes to determining "real" consciousness.

> If we don't think the candle in a simulated universe is a "real candle", why do we consider the intelligence in a simulated universe possibly "real intelligence"?

A candle in Canada can't melt wax in Mexico, and a real candle can't melt simulated wax. If you want to differentiate two things along one axis, you can't just point out differences that may or may not have any effect on that axis. You have to establish a causal link before the differences have any meaning. To my knowledge, intelligence/consciousness/experience doesn't have a causal link with anything.

We know our brains cause consciousness the way we knew in 1500 that being on a boat for too long causes scurvy. Maybe the boat and the ocean matter, or maybe they don't.

I think the core trouble is that it's rather difficult to simulate anything at all without requiring a human in the loop before it "works". The simulation isn't anything (well, it's something, but it's definitely not what it's simulating) until we impose that meaning on it. (We could, of course, levy a similar accusation at reality, but folks tend to avoid that because it gets uselessly solipsistic in a hurry)

A simulation of a tree growing (say) is a lot more like the idea of love than it is... a real tree growing. Making the simulation more accurate changes that not a bit.

You're arguing for the existence of a soul, for dualism. Nothing wrong with that, except we have never been able to measure it, and have never had to use it to explain any phenomenon of the brain's working. The brain follows the rules of physics, like any other objects of the material world.

A pen and paper simulation of a brain would also be "a thing happening" as you put it. You have to explain what is the magical ingredient that makes the brain's computations impossible to replicate.

You could connect your brain simulation to an actual body, and you'd be unable to tell the difference with a regular human, unless you crack it open.

Doing something merely requires I/O. Brains wouldn't be doing much without that. A sufficiently accurate simulation of a fundamentally computational process is really just the same process.

Why are the electric currents moving in a GPU any less of a "thing happening" than the firing of the neurons in your brain? What you are describing here is a claim that the brain is fundamentally supernatural.