When I was developing the level system I had the idea that the player would have to choose between a "drone" playstyle or a "gun".
but looking back at this aspect of the game, I see that I didn't put much thought into it, the level cap is just arbitrary and it would make more sense to add enough levels to unlock the entire skill tree.
I will fix this after the game jam voting period.
I hope that this mistake didn't ruin your experience :)