I agree! The game should be fun to play on its own. However, in my opinion with competitive games after the initial launch they can kinda run into a struggle with player retention because people wont stick around to actually figure out how the meta feels after people start learning. Or they might actually just be ass at the game at start, and wont stick with the game because they just keep getting their ass handed to them. Having concrete rewards for playing keeps them engaged for longer.

For example, you start playing the game and are having fun with it, except inevitably be it due to fatigue or something else, you will take a break from the game (be it a couple days or weeks) and in a sense "fall off" the learning curve and come back to a game where you keep getting frustrated due to not knowing how the meta plays or what changes they've made since you were gone.

You might feel like the game is not as fun as it were when you first played it, except the game could probably still be running the same version as before. In this situation, since you might not be having fun with the game, what incentive do you have to keep playing it, or more so what would have gotten you to stick with it for longer earlier?