How do you gracefully exit a strategic partnership?

I've exited many partnerships. One example was an early customer of a company, a product whose deployment did not go well, which did not help the brand of the IT department. I emailed back and forth with the CEO of this company and said, "I appreciate that you’ve tried to address the issue, but we're probably not going to continue." They asked how they could make it right, and I said, "The right thing to do is to give us back some amount of money, and we should consider a longer-term partnership when you are more ready."

The CEO responded positively to that. they turned up with a 90% refund on that subscription, which is unheard of in most cases. But I remember going back to the CFO to say, "This was not great, but this is what we found." And the CFO responded, "That's the sort of company you want to partner with and do business with." Four months later, when the product was more ready, we engaged more of a customer success function that was a better path to success. That product was deployed and continues to operate in that organization. Renewal increased over time, but value was demonstrated. The spirit of the partnership evolved.

I've seen bad partnerships turn into power struggles. Let's say you join an organization that has a bunch of contingency staff and they need someone to manage all that. Sure, they're bringing in a large staff, but that doesn't necessarily mean you have this fiefdom of people that out-power you. And then there's this just weird struggle.
When you say, "I need to be fiscally responsible. We can't have 100 service desk people in one building," there’s friction. Their response is, "This is how we've always been doing it. You just got here and have no context." In those situations it’s obvious that they're just not good partners, but at the same time you don't want things to break. You need to have enough confidence in yourself to make those decisions.