Close spaced gears tend to come into their own if you do a lot of group riding.
If you ride by yourself it doesn't matter if you cannot ride at exactly 16 mph.
One gear has a slightly too high a cadence that speed and the next gear up has a slightly too slow one.
So you'll tick along at 15.5 or 16.5 depending on which gear you use.
But what happens if a group ride is ticking along a 16 mph.
It's no fun/hard work to ride in that half gear situation.
As for gears, I'm an outlier .....
My old 3x9 setup didn't have enough range to suit me.
So for this new-ish setup I went for the maximized range that was easily possible.
A 3x3x9 setup was halfway there but I looked around something better.
I now run 2x2x14 which gives me 24 unique gears out of 56 with 13.6% between each gear.
My top gear is 19X larger than my first gear.
I tend not to use the bottom 3 gears (sub 4 mph) or the top 3 (over 35 mph) but they are there if I want/need to use them.
YMMV ..........