[AzMoo_]

You also pay for support so that when your senior engineers all pack up and start their own business together you can ring somebody to keep your infrastructure running while you find more people with the right level of knowledge.

[kikoreis]

Except that's not really what break-fix support covers. Specifically, support doesn't typically touch your infrastructure; it provides advice, documentation and patches which a local team needs to actually implement.

[AzMoo_]

Advice is the key here. If you're in a situation where literally your entire team goes then you've probably got bigger problems, but when you lose some key people having professional support available to guide your juniors is beyond useful.