Disappointment is equally a judgement of the thing itself, and the surrounding hype. It is unfair on the thing to judge it as disappointing, and yet, it is a visceral feeling that must be addressed.
A Taxi Driver has a 4.0+ score on Letterboxd. I expected pure cinema. Something to tug at the heart strings. Instead, I got a fairly stale, generic, stereotypical movie, that had emotional beats that were less tender and genuine, and more contrived and manufactured.
The best part of A Taxi Driver was exposing the politics and history of South Korea, something I never knew about.
It had the opportunity to say something about people being involved in social movements—the measurable sacrifice that implies. Instead, it creates caricatures of these people and honestly lends itself to the white-man-saviour trope.
It's servicable—if you have a beating heart, you can turn your mind off and enjoy the movie. I just couldn't feel that way.
Also, read the fictionalized elements, so it was not just insulting to the viewer, but to the subject it tries to "portray nobly".