Originally Posted by Mathalis

I guess I don't understand. Did they state a reason? What's the point of proficiency in a skill if it is not added to the roll?

It is added - the roll takes the bonus into account, and shows you what you need to roll to succeed, rather then actual DC.

So if OP was rolling against DC of 16 with +6 bonus, it will show DC of 10 and just roll d20.

I think the boon is that you just immediately know what you want to get when rolling. The disadvantage is, that it doesn’t communicate your modifiers to the check.. which I think is important.