I came back to reply with just this. Christopher Domas's conference talk on the movfuscator is legendary:

https://www.youtube.com/watch?v=R7EEoWg6Ekk

While this is true, I suspect a spec compliant implementation of the x86 mov instruction would many use more transistors than OP’s entire CPU.

Of course, but you don't have the toy CPU under your desk or in your laptop running at several GHz nor are you likely to find it in a target that really needs a cute hack to obscure your exploit.

> The Intel architecture is already Turing complete when you just use MOV instructions

No physically existing architecture is Turing-complete, since every CPU can (by physics) only access a finite amount of memory, which means that its state space is finite, in opposite to the infinite state space of a Turing machine.

But that's not a very useful definition so we usually don't both enforcing that constraint.