There's actually no contradiction. Marginal tax rates go down 6.2% at 118,500 when social security cuts out, and they only go up about 3% from there to 200k.
It's kind of outrageous, marginal tax rates going down for high earners, but there we are.
But thanks for pointing out that I had the wrong zip code, so I missed NYC income tax, which is 3.65% marginal, bringing average tax rates at 200k to 36%, not 33% (albeit with zero deductions and exemptions, which obviously isn't reasonable, you'll deduct state income tax at the very least and shave off 1.4% immediately).
Your link is in error, it treats Social Security tax as continuing past $118k.