The 2% target was never meant to be a ceiling. It was established as a minimum floor at a time when most European allies were spending far below it. The fact that reaching 2% is treated as an achievement rather than a baseline is itself a measure of how far European defence culture had drifted.
The critics who argue that the percentage matters less than what it is spent on have a point — but it is a secondary point. You cannot buy the right things if you are not spending enough in the first place. The sequencing matters.