Integrated supply chains are incredibly complex once you get to that level, and not really candidates for a new entrant. The big logistics players you list go after those contracts rabidly, and newly signed contracts have payoffs measured in decades.

It's a massive industry, nearly 1.8T$ this year. (Yeah, that's a T.) I'll be happy with carving out my little 50B self-serve niche before digging into integrated supply chains. :)