I'm not so sure of this, Intel's slides state 10nm still has better characteristics than 14nm+.
This was from Intel manufacturing day not too long ago:
https://3s81si1s5ygj3mzby34dq6qf-wp...ntel-xeon-process-technology-enhancements.jpg
They need 10nm++ to beat 14nm++ in performance. So the first two 10nm versions will reduce power and area required but achieve worse performance.
The reduction in power isn't so noticeable anymore either. The 22nm and 14nm process both brought minor reductions in power. The 40% performance stated for 22nm only came true for Bay Trail, meaning transistor-level improvements happen only for selective devices.*
*Big part of the reason is previously the process gains came easy and fast so there wasn't much focus on the architectural level. Ever since the gains started diminishing more advanced architectural features were introduced. Now, the gains from new process isn't as clear, not just because process itself has little gains. Technologies like C9/C10 idle states greatly diminish the impact of new process, because idle power is dependent on other factors. Transistor-level power reduction is only true for load, and that's what used to matter.
Let's see others which reduce the impact of a new process.
-Power Gating: Certain sections of the chip can be powered off to reduce leakage power which can become significant in lower power modes. A new process with improved leakage characteristics benefit only in situations where Power Gating can't be applied
-Heterogenous architectures and accelerators: These are circuits that can improve its performance either being wide and slow clocked or narrow and fast clocked. If the transistors are optimized for CPU, meaning high performance and clocks, it may limit performance of the said accelerators that best operate wide and slow. The same will be true by using GPU optimized transistors, which will slow down CPU-like parts of the circuit.
The choices that are made design-level start impacting how much gain a new process could bring. Of course the reason they are there in the first place is because new process does not bring as much benefits as before.