I'm not sure I agree. It's one thing to treat IT as a customer for a product or service your company offers. I don't doubt that the business also uses FB messen

I'm not sure I agree. It's one thing to treat IT as a customer for a product or service your company offers. I don't doubt that the business also uses FB messenger to communicate for example. But FB as a consumer product doesn't offer DNS or SAML or any of these other critical services, so why would IT share infrastructure for those? That's not dogfooding.