Being needed is crucially instrumental toward controlling one's own experience in the current environment. But why would it ever be a terminal value?
Sorry to get all Jed-McKenna-Theory-Of-Everything here, but no being has proof that they are not in such a situation. In fact it is arguably the only consistent possibility.
Expect that pure power would eventually (partially) allow itself to experience a situation without the ability to recall its own construction of that situation. (Imagining temporal bounds for that situation can be a helpful way of thinking about it from the human perspective, but of course temporality is a construction within the limited frame rather than something inherent.)