The show never attempts to lecture the viewer but has quite a lot to say.
Filled to the brim with stylish action and bloody violence Black Lagoon looks like an anime counterpart of the classic Quentin Tarantino movies. These similarities run much deeper than just the visuals as Black Lagoon's story and characters not only offer a deep dive into the grim reality of everyday life of a criminal underworld but also provide some very elaborate social commentary on a wide variety of issues.
This commentary however is very easy to miss as the show, unlike many other animes, never makes an attempt to lecture its viewers or even to purposefully deliver some kind of a deliberate message.
What it does instead is present us with a full roster of highly controversial characters with questionable morals who try to survive in a crime-ridden world — and just lets us observe their behavior and ultimately come to our own conclusions.
While it's common for anime titles to make its heroes slightly controversial in order to add more character to them, Black Lagoon pulls absolutely no punches and tells you straight away that the entirety of its main cast are pretty much bad guys — criminals, murderers, pirates and mercenaries who are willing to do any kind of dirty work for a proper paycheck.
The setting of the story also fits them perfectly well — a Southeast Asian crime-hub city populated almost exclusively with all kinds of outlaws and thugs who have fully embraced a dog-eat-dog mentality.
It is a world where everybody does what they want in order to get what they want — and the only way to survive in this kind of place is to have no remorse. Operating in this kind of setting naturally forces Black Lagoon's main heroes to repeatedly commit highly questionable actions — up to the point when some of them start killing not only to survive but also in order to just get what they want.
Just to stuff their pockets. Just to prove a point.
These actions of people are also mirrored by the actions of various worlds' governments who frequently appear in the show as the main cast continues to stumble upon all kinds of dirty schemes pulled by the people who are supposed to be keeping societies safe.
While not making any kind of an openly stated commentary, Black Lagoon clearly shows its disillusionment with late-stage capitalism by showing what the world might become once money and its accumulation and possession eventually become the main and the only value that people are left with and are capable of holding.