The story desperately lacks obstacles. The entire police investigation, for example, is pointless, because it is way too much straightforward and doesn't encounter any significant difficulty. This is almost true for the rest of the movie as well. Even when the screenplay is about to hit a climactic point that could have generated great dramatic tension, it choses the peaceful road instead.
Yet, because maybe that's how life feels when you're 88, and because Eastwood's character literally says it in the movie, he "just wants to enjoy life", there is a strange and poetic feeling that comes with watching such conflict-less and absurd story, which, overall, is somewhat enjoyable.
 <spoiler>When Earl learns from his grand-daughter that his wife is dying, if he decides to go see her, he takes the risk of leading the cartel to his family (they didn't know he even had a family); yet this is the final chance of his life to prove to his wife that he cares. The screenplay avoids this conflict by making the cartel guys "lose him", and even more ridiculous, having them being emphatic about his wife's death when he comes back. (Other movies have teached me that the cartel aren't emphatic about wives' death, as they're usually the ones killing the wives.)</spoiler>