How are you getting to this conclusion? Being in an offside position is not an offence - a player standing in an offside position not interacting with the ball/another player etc will not result in the referee taking any action. The offence is [doing something] having come from an offside position. Seriously re-read @Peter Grove's excellent post above regarding the difference between offside position/offside offence, I think that's genuinely one of the best explainers I've ever read on the subject.You probably have summed it up better than me! I still dont see how you can commit an offence by NOT committing an offence though. 'It is not an offence to be in an offside position' yet it now is.
2 things required for an offence: being in an offside position and interfering with play. The former is judged at the moment the ball is played by a teammate, the latter can happen at any point between the pass and a play by a defender or the ball going out of play. When both conditions are met, play is stopped and the IFK is given from the point where the offending player is stood at that moment.You now can also commit an offence in a part of the field that its not an offence to commit the offence that you didn't commit in the first place. No wonder we can't get enough refs!
I think you're thinking of the offence having occurred at the point the ball is played, but that's never the case. At the moment the ball is played, the AR registers a player in an offside position and then monitors their actions. There cannot be an offence at this moment.
At some point later on, either a) the player who is being monitored will [do something] to interact with the play, in which case we have both offside criteria met and flag for an offence where the player is at that moment, or b) the ball will be played by a defender or go out of play and everything resets.