I'd say block validation rules are an extendable set of rules, and what moves them is consensus, because they only work if everyone on the same chaintip enforces them in exactly the same way.

"Consensus rules" is perhaps a misnomer because the rules do not describe consensus. Instead consensus is formed over these rules, or else it won't work for anyone. The rules come first: someone codes them, then you review, compile and run them, and finally, you running them makes you part of the consensus that these are the rules; not the other way around. It's still semantics though, but because consensus is a popular word nowadays it can be confusing af in some contexts at times.

It's easier to discuss this in a non-adversarial setting, and I took maybe an hour over first coffee to write and rewrite that comment, free it of aggression for the most part and take a step back and read it through / tune it a couple of times before hitting reply. That's much harder on X than it is on SN.