They are on 5nm so they can actually use more transistors right now until everyone plays catch-up.
Apple have a full ARM architecture license so their designs are very different from the vanilla off the shelf ARM ones, hence the large performance gains.
It's irrelevant to end users on where you choose to draw the line on the semantic debate on what a SoC is. Benchmarks beat semantics.
These chips are being used in the same chassis so they are a direct replacement for the Intel parts.
Zen 3, the King is dead!