So, Will smith can act. He can do a range from comedy to action, to the difficult to make work action/comedy. He can even do drama (try Pursuit of Happyness, 2006 or Seven Pounds, 2008 if you missed Smith in something dramatic...and good).
Unfortunately, Smith being a capable actor placed next to his kid who can't act makes it REALLY obvious that his kid can't act. (Incidentally, Jaden WAS also in Pursuit of Happyness and, apparently, more capable at 6 years old than in his terrible roles since).
Mainly, this movie was annoying. I felt bad the Smith's character and for Smith himself. Jaden's character is a brat that doesn't really have to grow and evolve. Based on the few pictures I've seen of Jaden when I googled the film, it looks like Jaden is just playing...Jaden.
This movie is entirely forgettable. Jaden is the main character and Will Smith is support. Jaden just doesn't have the chops to make that arrangement work. Add in the fact that Jaden's character is just terribly written (probably so he didn't have to actually act much) and that the premise of the movie combined with the somewhat forced finale is just meh, at best.
Skip it. If the premise of a parent and child operating together on a dangerous, uninhabited planet and trying to find a way off interests you, I recommend Prospect (2018). That movie is not as flashy, not as big budget and is more slow burn, but ultimately has better characters and a more interesting story than the flashy "my daddy put me in a movie" garbage that "After Earth" serves up.