Well done. You've solved the security challenge of our generation.
And all it took was meaningless buzzwords which almost all enterprise companies at least do already. It doesn't make one iota of difference when your vendor equipment or services are compromised.
Limit the attack surface all you want, there's still an attack surface, and state based actors are highly motivated to put extreme pressure on these. It's nearly axiomatic that there is no perfect security, and to expect a company to defend against all attacks from organizations whose cyber warfare budget exceeds the company's gross revenue is unreasonable.
And all it took was meaningless buzzwords which almost all enterprise companies at least do already. It doesn't make one iota of difference when your vendor equipment or services are compromised.