While Rambo: Last Blood was a majorly disappointing addition to the Rambo franchise, it was partially Rambo 4’s great ending that set back the sequel. The Rambo series went through a strange evolution throughout its five movies. While the original Rambo: First Blood is a thoughtful, bleak thriller about a traumatized soldier returning from Vietnam and struggling to cope with civilian life due to his PTSD, Rambo: First Blood Part II is a jingoistic action movie where the same character mows down scores of faceless enemy soldiers in the name of freedom. By Rambo III, the character was jetting across the globe to fight another war.

https://screenrant.com/rambo-last-blood-problem-rambo-4-ending/