It is really simple, the jump shot is allowed and is part of the game. Jumping with full length cue and with a jump cue are skills. So when you deny yourself a skill while others have it you put yourself at a disadvantage. Let's say you choose to forgo jumping and focus more on other aspects and you do end up being a better pocketer than your friends. Ok so you are now pocketing at say a 580 speed and you meet other 580s who also know how to jump and how to play safe against the jump. When shots come up where jumping is an option or might be the best choice you won't have that option and they will. So really all you can hope to do is play tight safeties to try and nullify their jumping ability. But the odds are that you will not be able to do this as much as you attempt to. Meanwhile an opponent who does know how to jump can push to a jump shot, play safeties knowing that you will always kick and have a much wider range of shots available to them than you do.
there really is not a need to choose which aspect of your game to improve. You can do both daily.