You are wrong. The Snapdragon X Elite is actually a great example, unlike M1 it's performance isn't particularly great and it eats 50W under load. That makes its CPU cores a fair bit less efficient that AMDs even on the same production node. If Apple Silicon didn't exist then you might instead argue that x86-64 is more efficient than ARM.

If all that's true then why does Snapdragon have better battery life? As I said in my comment the great battery life comes from when the CPU isn't being used. It's everything else around it. That's where AMD is still significantly behind.