Of course it's noticeable. I use a 180g phone(s21 fe) and am used to it. I tried a 200g phone(oneplus 11), and it felt heavy in my hand and on my pinky shelf. My wife's phone is 230g(s23 ultra), and I don't see how she uses the thing. I mockingly do a bicep curl with it every time she asks me to hand it to her.
They weight 10% less and our brain notices this.
According to Drang, the reduction in mass happens mostly around the perimeter of the phone, which reduces the moment of inertia (making the phone easier to manipulate)