Not really. Most of those companies have lax Cloud Cost Management hygiene and/or the Cloud Platform team is separate from the Infra/Servers team.
If you are F250 you can probably negotiate a nice discount if you are able to fully migrate to a single cloud, but most companies don't want to keep all their eggs in a single basket. This means larger organizations cannot avail competitive discounts on public cloud.
By bundling Private Cloud (VMWare ESXi), Network Security (VMWare NSX), APM (CA Wiley), Endpoint Protection (Symantec Enterprise), and Data Security (Symantec Enterprise) I can purchase 5 critical pieces of Enterprise Infrastructure using a single PO. This is critical at large organizations as any PO above $30k almost always requires CFO or Comptroller approval, and a single PO to Broadcom satisfies your Infra, DevOps, and Security needs (which are all cost centers if you aren't a tech company).
Btw, Broadcom themselves is almost entirely on GCP [0]. Almost all their infra and products are served using a GCP stack on the backend.
[0] - https://www.broadcom.com/blog/broadcoms-transformation-journ...