Every prompt and answer is contributing value toward your progress toward the final solution, even if that value is just narrowing the latent space of potential outputs by keeping track of failed paths in the context window, so that it can avoid that path in a future answer after you provide followup feedback.
The vast majority of slot machine pulls produce no value to the player. Every single prompt into an LLM tool produces some form of value. I have never once had an entirely wasted prompt unless you count the AI service literally crashing and returning a "Service Unavailable" type error.
One of the stupidest takes about AI is that a partial hallucination or a single bug destroys the value of the tool. If a response is 90% of the way there and I have to fix the 10% of it that doesn't meet my expectations, then I still got 90% value from that answer.