closer ratios between commonly used gears, the ones we use most of the time--here are some Sheldon Brown charts showing a 50/39/30 + 12-28 ten speed vs a 50/34 + 12-32 ten speed (the 11 speed 11-32 just has the 11 added on, rest is same)

the Sheldon Brown chart can't do 11 speed cassettes, but at least it shows the % between shifts (and the 11-32 t

the thing to look at is the percentage of jump between certain gears, and one tooth differences tend to have around 7%, we all know how that feels nice, and a triple and a slightly tighter cassette shows how in the most commonly used cogs, you get more closer shifts compared to a compact and wider cassette.