Bowles-Simpson revisited

If you examine the comment thread from my previous post, you will see that a reader argued I had overstated my critique of Bowles-Simpson, and that I largely conceded his point. My main pleading here is that, because I was focusing on my critique of 1986-style reform, I ended up using Bowles-Simpson as a straw man and thus, e.g., treating its revenue gain from tax reform ($180 billion for 2020) as a mere triviality. But what's $180 billion among friends?