So true. If the dice were created equal (as far as number of success versus failure symbols goes) only having more dice would mean a greater chance of success. Now people can give it a shot to try and roll when their ability dice number does not equal the difficulty number (and as such the number of purple difficulty dice). The same applies to setback and boosts, and even a very slight difference between proficiency dice and challenge dice.
But it does make everybody seem more capable, as the success ratio is slightly higher than the failure ration. And that translates to highly skilled characters even seeming, or simply becoming, more capable.