I find, well, for my style of riding, 21 ratios more than enough, in fact I probably only use a fraction of those 21, it might be interesting for me to actually watch what ratios I am using. I am sure everyone has a favourite ratio, a gear selection they are most comfortable with, the terrain gets harder, you change down, but as soon as it gets better, I bet everyone tries to get into their favourite ratio. But, that's my thoughts, as I am happier cycling slower if it is more comfort to me, my favourite ratio. Bombing along, nah, the faster you move, the faster you have to think, and I can't be bothered thinking fast, too much like hard work when I am taking leisure.
Incidently, my ratios are not standard, when building the bike, well, taking the bits off I did'nt want and fitting bits I did want, I mixed the individual cogs of three cassettes, with emphasis on many teeth, for the hills around here. I will see how it goes, one does not know if they do not try.
Oh, there are some Rohloffs on fleabay, what a price tag !!!, hardly viable for most.