The ending

He realized they weren't a good pair.

He probably "switched back" to reality and realized the cleaning lady told the model that she was gonna go with her intending to kill her so she could have the handsome young guy all to herself

he was finally free.

He was running because he probably bumped into the vendor as well, so he realized that the island was inhabited. Then he put two and two together: if they are not really in danger, Abigail might want to kill Yaya so she can stay in charge, since they will probably come across other people too.

I believe the last shot is supposed to represent the main character being punished for his sins. On the surface, the film is about class divide and rich vs poor, but I think it's actually an anti-feminist film about what happens when men roll over and let women take charge and allow everything to go hell.

Throughout the film, men are spineless, passive, trying to conform to the current feminist nonsense that men should "back down" and let women take charge and yadda yadda. The main character buys into this notion and continuously lets women domineer over him to one degree or another, first with his model girlfriend who he essentially treats as a sugar daddy, then later with the cleaning woman who he sells himself to in exchange for food and favor.

The ending, when he's running through the branches and cuts are accumulating throughout his body in ways reminiscent of someone being whipped, seem to suggest he, and all men in a way, are being punished for their passivity and allowing the disasters of the film to unfold.

He's not the only passive man in this film. The captain, who should be in charge, instead hides in his room neglecting his duties and getting drunk, letting the very masculine looking second in command female officer make decisions for him that eventually lead to the ship sinking and most of the passengers dying, the wealthy "shit" tycoon being unable to control his older, pompous wife, who ends up forcing the staff to take a swim that inadvertently causes the wacky dinner vomiting scene, the wife of the arms dealer who picks up a live hand grenade tossed into the boat by pirates who, instead of throwing it overboard as she should have done (and as her husband attempts to do the moment he realizes what it is), just wonders out loud if it's one of theirs, etc.

The film seems to be suggesting that everything that goes wrong in it is because men have failed in their duty as men, and the final shot serves as punishment for their passivity.