What results is more of a cat and mouse game than a classic whodunit. And you have an emotional connection to the protagonist to boot!
It teaches exactly what it means to be a hero, the feverish persistence to do what is right no matter the costs.
Endgame meets expectations without really ever exceeding them.
For the most part, the film is successful, mainly because Marvel has done a pretty masterful job of laying the groundwork during the past decade of MCU movies.
To say this film is heavy handed is a huge understatement, the metaphor of the train classes to the classes in real life is over done and really not subtle at all, we are beaten over the head with it.