Everyone in bodybuilding or adjacent crowds already knows this.

How fat you are is entirely a function of how much you eat. If you want to put on weight, you bulk by eating more. If you want to lose weight, you cut with reduced calories.

The idea you could instead bulk by doing less cardio and cut by doing more sounds completely crazy. In reality, you do more exercise on a bulk because, duh, you can recover from more volume when eating a surplus.