How does low voltage help? I mean, you can lower the voltage to increase efficiency on any chip. Nobody does that because it is a waste of expensive silicon.
People definitely do that, the voltage you chose to power your chip is always a consideration, it's one of the variables used by laptop manufacturers to manage thermals, and it's also pretty common to lower the CPU voltage so that you can run a desktop system with passive cooling.
Anyway my point is that you can lower the voltage on any chip so the fact that this runs at a low voltage isn't noteworthy.
To the OP: yes this is trading silicon (aka area) for efficiency. That’s the whole point.