TSMC is not trailing. They’re so far ahead that Intel’s 18A is equal to their N5 family in density.
Therefore, N2 is 2 generations ahead of 18A by definition.
Therefore power advantage you’re referring to is backside power delivery. This is a need long term but it doesn’t bring as much power benefits as you think. TSMC’s customers don’t appear to demand this feature as highly since it’s been getting pushed back to 16A. The design change for designers don’t seem worth it yet.
