Can you tell whether you work in a product design company, or an engineering company?

Does that come from clients?

I used the same 3-in-1 latch circuit for power on/off, pairing, and software power off for 12 years.

A good enhancement mode NMOS FET can be as good as a physical switch at low voltages.

If you really need nano-amp level leakage current AND very low drop, you can consider turning to beefy depletion mode devices, which gate the user will discharge with the button press. A nice benefit is that you can directly sense the button press with an MCU.

I once even did a bluetooth mouse with this "hardware" switch, and a graceful shutdown: we sense voltage on the buck capacitor, and detect when the battery disconnect triggers.

The few microfarads in the capacitor are enough to send the last update with the 0% battery level, and a disconnect command.