But 2000kcal is already well below a male doing normal things during the day; so 2000 + gym with weights would drop that completely out. When I do weights I try to shoot for around 2500 which already sucks compared to what I was used to (which does affect performance but it feels the same so I think overall I benefit?). But when just doing cardio I can go well below 2000 on a day or just not eat at all (only tea + water) and feel sharp, I just choose not to and just do days without any food.

I cannot imagine doing every day below 2000 and then going to the gym indeed. That would definitely not be productive and painful, but doing days of weights with 2500 max, other days around 2000 and then some days 0 works fine for me.