Every high-grossing title has spent years learning from its mistakes by leveraging—and iterating on—feedback from players. You can avoid those same mistakes by studying those games, and learning where there is room for even more improvement to the player experience.
All the options and methodologies for testing your own game are also available for competitor analysis. This means you can run anything from a quick usability-focused check to a large-scale quantitative analysis of appreciation data, laying the groundwork for your own benchmarking.