I wrote a somewhat long analysis of Da 5 Bloods some time ago. Might as well copy and paste my thoughts here:

WARNING: spoilers below
One of the main themes of the film is on the generational impacts the U.S. left on Vietnam after they pulled out and how those involved with the war on all sides (U.S., France, and Vietnam) never fully recovered. This is a key motif which recurs multiple times.

For instance, the significance of the LAMB team shows that many landmines planted during the war are still active and that people are still being blown up by them to this day. While LAMB isn't a real group, other groups in Vietnam are actively working to locate and remove landmines left over from the war. That two people are lost to landmines in the film (David almost succumbs to the same fate) makes this theme even more profound as it shows how easy it is to walk over and detonate them.

This also extends to Otis, when we learn he had sex with Tiên, a former Vietnamese prostitute and impregnated her during his time in the war. Unintended pregnancies were a consequence for Vietnamese prostitutes of the time and that extends to this sub-plot. One conversation between Tiên and her half-Asian daughter reveals that her mother never told her about Otis and hints of the emotional conflicts this caused some Vietnamese families in the country.

This also applies to David, who faces constant rejection from Paul, his father and the most unstable of the four Veterans. Though we don't find out the reason Paul's PTSD has effected him so heavily until the last act of the film, the impact this has on his son is shown in vivid detail. David's monologue on the death of his mother shows that, due to Paul not opening up about his PTSD, David thought it was his fault for his strained relationship with his father. This hints that other American families might have suffered from this as well.

Other generational effects of the war are also briefly explored by the film, like the mention of Agent Orange during the film's opening (a herbicide that has been linked to multiple birth defects which continue to occur today), an early scene of a Vietnamese kid (notably missing a leg) asking the men for money, a later scene where a worker in a floating market accuses Paul of murdering his parents, or how one of Desroche's men accuse Paul of murdering his brother.

Another interesting motif is how the gold bars change in significance as the film goes on. Throughout the first half or so, Norman mentions that they should keep the gold for themselves and treat it as reparations for all the struggles black people have faced in the U.S. Since Spike Lee often works the current political stance of black people in the U.S. into his films (like the mention of Black Lives Matter during this film's coda), I think the gold bars symbolize the current political discussions of reparations for slavery. Spike Lee appears to take a pro-reparation stance in this film. Once Desroche and his men betray the veterans though, the gold represents opportunism, shown by Desroche's false promises to the group and him taking advantage of them. This opportunism, however, doesn't really apply to the French as much as it applies to the U.S., which is why Desroche puts on Paul's "Make America Great Again" hat right before the final shootout (Spike Lee criticized Donald Trump during the terrific coda of BlacKkKlansman and the MAGA hat in this film is another extension of this recent motif).

There's a lot to be said about the arcs of the four Veterans. Eddie, for example, is initially thought to be wealthy by the other veterans, but he eventually opens up to them and reveals that, due to multiple instances of poor management of his money, he became poor. Revealing this to them shows he finally found the emotional strength to move past it. Melvin also grows throughout the film when, after learning of Vietnamese soldier Milton L. Olive's sacrifice during the war, says he wouldn't ever do the same for them. During the final shootout though, he makes the same sacrifice Olive did and goes out as a hero. Otis also changes by choosing to spend more time with Tiên and their daughter at the end of the film. While it's assumed he rejected them for a long time (resulting in his daughter's uncertainty over who her father was), his decision at the end to reveal his identity to his daughter alleviates this stress from both of them. Lastly is Paul, who undergoes the most memorable arc in the film. His PTSD has haunted him more than it has for the other three veterans and while the cause of what's been tormenting him for so long is left ambiguous throughout most of the film, it's eventually revealed his PTSD stems from how he accidentally shot and killed Norman during a shootout. Before he's killed by Desroche's men though, he makes peace with Norman and his guilt during a hallucination where Norman "forgives" him for shooting him, resulting in him fearlessly accepting his fate.

Spike Lee also fills this film with some effective stylistic choices. For instance, most of the soundtrack comes from Marvin Gaye's 1971 album "What's Going On", which fits the film's themes really well. The songs in the album tell the story of a black Vietnam veteran returning home only to witness racism and other forms of hatred. This cleverly ties in with the generational themes of the film. I also liked how the flashbacks were shown with a widened aspect ratio and were shot via 16 mm film, a type of camera which was common during the time those scenes took place. In addition, the occasional classic film references (Apocalypse Now, The Treasure of the Sierra Madre, and The Bridge on the River Kwai) were pretty clever. Granted, the inclusion of Ride of the Valkyries was a bit on-the-nose, but the other references resonated with me really well, like Paul's slow descent into insanity during his walk alone in the jungle being a reference to the voyage to Kurtz's compound in Apocalypse Now (Paul walks through a river at a couple points during that sequence, in fact), or Otis repeating the final lines of The Bridge on the River Kwai after the final shootout, which, like the ending to David Lean's film, led to multiple casualties on both sides of the conflict.

Overall, I loved this film and appreciated Lee's approach of showing the full picture of the Vietnam War, not just one aspect of it. While one could call this approach overstuffed, I instead found this to be really effective as it made for a truly thematically rich film that represented the various attitudes and beliefs concerning the Vietnam War.