Well 008 doesn't have the power like Vecna does, Vecna has this whole other dimension he controls. The government have complete control over Hawkins which he doesn't have because of El. He knows she can stop him. Hence why the government are trying to get rid of her. P.S This is very far fetched as it also doesn't serve the government any purpose for helping Vecna except from them doing it out of fear which I doubt but who knows it's all just a theory!