On its face, this seems a little like sour grapes from FedEx. "You're going to leave us, so we're going to leave you first." While Amazon is _absolutely_ becoming a last-mile competitor—I see their blue vans all over the place now—they aren't there yet, and still worth 1.3% of 2019 sales now. Why not take the money and extend your runway to "reduce dependence"?

So then to answer my own question, I'd hypothesize that it's a combination of bad-deal economics (e.g., Amazon contract isn't that profitable in aggregate) and strategic focus to spend time and energy on the post-Amazon _future_ rather than the present. Which I get.