Is anyone at Larian studios familiar with math and probabilities?
Passing one check requiring 16 or higher on a d20 = 25%
Passing two checks requiring 16 or higher on a d20 = 6.25%
Passing three checks requiring 16 or higher on a d20 = 1.56%
And when all three checks are required to pass for an outcome to occur, well, good luck.
Yes they are quite aware : there combat system uses percentages.
Which is why most social/dialogue rolls have a base DC of 10 or lower ! If it is higher, it is because they feel that NPC does not want to move on that point.
nb : I see your point though, related to the topic here. But most DC are 10 - your skill bonuses.