If we take the argument from first principles I'm not so sure it leads to your destination. Are atoms more or less complex than the things they comprise? And is that complexity not encapsulated by the emergent system that forms from that atomic substrate?
I'm frustrated that people are talking to me as if I want to discuss the complexity of things, when I thought I made it quite clear in multiple comments in this thread that that is not what I'm talking about at all.
When you are arguing, or even discussing, with someone it's an asshole behavior to tell them "what you are discussing has no foundation, or is irrelevant to me, so I'm going to discuss this other thing instead." Maybe just politely opt out of the argument at all with an "I disagree".
This is the point I've been making. An asshole, or at least childish, way of arguing is to respond to someone who said "this thing is most complex", with "well I disagree, because two of this thing is more complex than just one of that thing". It's like a kid saying "infinity plus one" to one-up the other kid.
One can have a philosophical conversation of the salience of various perspectives without telling the other person "your perspective is unimportant compared to mine, because it doesn't meet my personal threshold of salience". Yes, no duh, people do not find the same perspectives salient. If you're talking about policy, then salience can be ranked, if you're talking about personal opinion, then salience can't be ranked.
You have this kind of philosophical discussion, politely, by acknowledging the other person's point and indicating that you want to talk about something adjacent. Not by telling the other person they're overlooking your point (and in the very act of saying that demonstrating that you are overlooking their point.
You literally said that "the brain is the most complex object in the known universe", which is an incorrect statement. If you didn't wanna discuss complexity, maybe you should've phrased things in a way that doesn't discuss complexity, but rather actually says what you want to say. The brain is obviously not the most complex thing in the universe, and I can't even imagine why the hell would you think it is.
But nah, it's much easier to insult people for not understanding you, rather than try and make your point clear.