We use terms like 3.0 and 4.0 because they are terms that have acquired general meaning among pickleball players. Most have an idea that a 3.0 player plays like this and so on. For the same reason, we use the numbers as a way to help players situate themselves initially along the path.
Other than using them as shorthand, we do not focus on the number assigned to a player. Rather, we focus on the pieces that, when added to your game, will result in playing at successively increasing levels. In other words, we focus on the process. The result - whether it is a numerical level, a medal at a tournament, an invite to play in a different group, gaining confidence in your play, winning an extra game - will flow from an improved process.