By the laws of physics, it's pretty clear we don't. The same chemical and electromagnetic interactions that drive everything around us are active in our brains, causing us to do things and feel things. We feel like we're in control of it, we feel like there's something there riding around inside. We grant that other people have the same magic, because I clearly do. But rocks, trees, LLMs, those are not people and clearly, clearly not conscious because they don't have our magic.

Hard disagree. We reliably operate with the concept of a self that’s distinct from others. The chemical and physical processes change in response to stimulus.

Indeed. We assume a lot, because we don't know. We don't have have settled, universal definitions of what consciousness means. But that also means that while we like to rule out consciousness in other things, we don't have a clear basis for doing so.