Being at a slight deficit won't hurt your soccer performance. You're not a top tier professional that needs to optimize for every tiny thing. Even if you are, Ronaldo is shredded and is a top 5 footballer. And most footballers are naturally very lean, so what you're saying doesn't even make empirical sense.
Should you expect to play the Champion's League finals while preparing to do poses at a bodybuilding show and do your best? No, but you could conceivably do these a few weeks apart.
Cardiovascular activity won't "kill your gains", there's no such consensus, you just have to be smart about your caloric intake.
There's no physical law involved here so saying it's "just physics" sounds very dismissive.
All these examples are very poor, bending reality to prove cliche folk wisdom, it’s actually kinda funny.
I gave you two disciplines: bulking up in the gym, or playing soccer...
while bulking up, you gain both muscle and some fat, and your soccer performance will suffer as your weight will increase, and your larger biceps and pecs really wont help your soccer game much (there is a reason that pro soccer players don't look like body builders). Also playing lots of soccer will hurt your 'gains'. (too much cardio is a 'gains' killer).
On the other side, while 'cutting', to be leaner, you are running on a calorie deficit for multiple weeks, or months, and your soccer performance will suffer since you are so glycogen depleted.....
You can be good at both, but not the "best you can be" at both disciplines at the same time as optimizing for one, will hurt your other one, and that's just physics.
Hope that makes sense....