The visual representation in this game (the jump) is an animation that could be represented by anything for disengage, for simplicity sake they made jump and disengage the same action. Enemy targets that disengage do not jump and instead create a sort of "whirl" of wind at their feet to show they are able to move away without an attack of opportunity.
Currently in game you don't have to even jump behind a target...you can...sure, but if you just use your movement to walk at a slight angle to the target you can gain advantage. People jump because it is easier to do without having to look to see if pathing is going to force you to walk too far out and cause an AoO. If they replace disengage with a different animation, all of the sudden your immersion breaking problem looks natural again...the actions are exactly the same though...so I feel that is just a shallow level of thinking on your half.
Now the argument on if disengage should be an action versus bonus action is another issue. I guess rogues have cunning action that is unique to them to allow this, so the above scenarios to permit sneak attack still work.
For the perception that "anyone" can backstab even in heavy armor....only rogues are getting the sneak attack bonus damage, the other classes are simply gaining advantage to get 2 dice rolls. It is not immersion breaking to believe that if I get you off balance and get to the side of you, it is drastically harder for you to defend yourself while it is easier for me to land a hit on you.
Just because you can't visualize or process these actions anything other than a surface level verbatim definition does not mean it is impossible and immersion breaking. Your lack of imagination and adaptability makes scenarios you are not familiar with limiting to you.
As far as breaking combat, again the rogue can already gain sneak attack through smart use of tools and should be aiming at getting bonus damage as much as possible otherwise they are not using all of the tools available to them as a class and is a misuse of your skills. Because people are more being efficient, does not inherently mean the game is being broken.
First it is immersion breaking cause that can't happen in real life, and then real life is nothing how D&D works and can't happen that way...can't have both.