You're wrong about that. The big hosting providers do not put public cloud hardware next to dedicated hardware. Public cloud hardware goes in big, homogenous

You're wrong about that. The big hosting providers do not put public cloud hardware next to dedicated hardware. Public cloud hardware goes in big, homogenous racks in a specific area of the datacenter. Dedicated hardware is very mix-and-match; you have all sorts of servers and network devices racked together. Connecting the two environments is no small feat, given the VLAN limitations of most current switches.