Size does matter. Of course there may be certain % of women that prefer smaller. There's all types of fetishes out there. But in my experience it matters, when my girlfriends and I get together for drinks and one of us has met a new guy, its like one of the first topics that comes up. "How big is he" My experience maybe a bit skewed since I tend to have pervy friends lmao.
I think many women when asked publicly or by men will say it doesnt matter, just so they don't hurt anyones feelings. Plus society has a double standard to some degree still, if a female comes out and says "Yeah I prefer big dicks!" some will judge her with ridiculous assumptions "She's a hoe, she must be loose etc". Meanwhile men can say they love big tits or big bootys lol.