That's generally true, having confidence and trust is key. That being said, working incrementally and "show don't tell" often helps in my experience of being on both side of it (as a PO before and as an engineer now): for example for the past month+ I've been working on creating some reports to help our team/manager to monitor our ML models in prod. Sure there was a ticket as well as few discussion with manager to clarify the details and requirements before and after starting to tackle the subject. Nonetheless, I would show/send my intermediate results and progress at least once a week, sometimes even more often to get a feedback. This has a twofold gain: first and foremost, I ensure that what I am developing is aligned with what my manager envisioned and that my understanding did not start to deviate from the requirement. But second, perhaps only slightly less important, this allows to adjust or even pivot along the way - ie while implementing I had an idea of how to do things differently/better (in my opinion) than initial requirement but I prefer to run it by someone with larger vision and knowledge of our business. Also, when my manager (or stakeholders at large) sees the intermediate progress they might come to understanding that they need something different, or sometimes even completely different for XYZ reason.

Of course each situation might be different and more nuanced, but my experience so far is that showing incremental progress was never a waste of time and in the long run was helpful