It's not how many .. it's the ratios .. You can change where the range of the 3 gears falls, by changing the external cog from 13 to 22 tooth,
and or chain-ring.

I'm using my Brompton's 3 speed with a 2 speed crank, the Schlumpf Mountain drive, which is another planetary gear,

and now, adapting to my hilly town, I have 6 'speeds' the 3 in the hub are used twice, still no derailleur to get bent,
still just one cog.. one chain-ring..