Multicloud is mostly about operational changes. Making distributed pools of resources behave as one cohesive infrastructure requires over-the-top orchestration and automation, end-to-end across the entire enterprise network from the data centre and public cloud to the cloud on-ramps in the campus and branch.
None of that is possible unless the underlying network is capable of plugging into an end-to-end orchestration platform. So enterprises looking to build multicloud networks should begin by ensuring their underlays are multi cloud-ready.