It's how tax brackets work. Notice the "+X% over the excess / of the amount over" wording in the documents. I'm not a CPA, so maybe one can chime in with a counter example of someone who would take home less if they made a larger salary. But I'm pretty certain this is how it works.
https://taxfoundation.org/2017-tax-brackets/
https://www.irs.com/articles/2016-federal-tax-rates-personal...
It's how tax brackets work. Notice the "+X% over the excess / of the amount over" wording in the documents. I'm not a CPA, so maybe one can chime in with a counter example of someone who would take home less if they made a larger salary. But I'm pretty certain this is how it works.