I came to the realization that the movie feels boring because there aren't any stakes. None that have an actual impact on the story, anyway. Like you said about Searcher just accepting his dad's return 100%, anything bad that happens is immediately dismissed. 25 years of your father choosing to abandon you can't go away in whatever small time frame the bulk of the movie happens in. The characters have no agency and it feels like they're there as plot devices to sell a plot no one cares about.