D2D for print books will not replace Amazon KDP for most authors—the royalty difference is just too significant if you're primarily selling direct to consumers online. But it's not supposed to replace Amazon; it's supposed to complement it.
Draft2Digital (D2D) saves you from becoming a part-time platform management specialist. Instead of spending hours learning interfaces and keeping track of multiple accounts, you can focus on what you actually signed up for—writing books and connecting with readers.