The trouble with a mechanical off switch is that you cannot easily / periodically turn it on, so it depends on your usecase.
AVR Picopower has been around for about 10y now. These devices dramatically drop power consumption to the point where batteries should last a very long time, definitely >1y, more like 3-5y.
The fact that modern devices drain a lot of juice is either sloppy SW design or sloppy HW design, since I believe the cost for microcontrollers is very similar.
That's the point though, in this case off means off. There is no reason his controller should have to periodically turn on, when you want to use it you turn it on.
AVR Picopower has been around for about 10y now. These devices dramatically drop power consumption to the point where batteries should last a very long time, definitely >1y, more like 3-5y.
The fact that modern devices drain a lot of juice is either sloppy SW design or sloppy HW design, since I believe the cost for microcontrollers is very similar.