Climbing on most of my local trails would involve a low, low ratio for a s.s., not really practical for the flat bits. No need for 24 or more though.
Wide spread cluster and medium chainring would get you 80% of the way there. 1x5 seems possible, with a rear changer that could handle the extreme difference.
Practically though, 2x8 has proved adequate on just about anything, with a bash ring.
So that is about ten gears effectively.
Pressing on, and making the most of the terrain, would benifit from a closer packed cluster, so more to get the extremes. For racing I can see the desirability for more.
My ideal would be a cvt of some kind.
In reality my next radical (for me) change is going to be to try a flip flop s.s. to see how it feels. Going 29 er at the same time.
The doctor diagnosed me with hereditary diarrhoea. I can't understand, I wear a kilt.