I'm sure it matters, but in most cases, I'd wager that not having that expectation met/exceeded is more of a disappointment than a complete dealbreaker.
I've never had complaints aside from one specific girl off Bumble.
We matched several years ago, and the conversation was going in a sexual direction, so she stopped me and asked me how big it was, saying she has a requirement of 8 inches or more. I told her that while I'm well-endowed, I'm not quite THAT well-endowed. She apologized, said that we should not meet then, and unmatched me.
More recently (maybe a year or so ago), she showed up in my feed again, and we matched again. I told her I was surprised she swiped right since I didn't meet her requirement last time, to which she told me that she was attracted enough to me to be more lenient. We went out for some drinks, things went well, and she ended up sucking my d*** in her car.
Later on, when I tried to set up another date so we had somewhere to f*** she told me that she thought she could be lenient, but that she really just needs 8 inches...and again apologized for wasting my time.
For context, this isn't like a big girl with a massive a** or something - she was probably 5'9", maybe 120lbs. I did a quick Google search, and it seems in the USA, based on self-reported data, only about 2% of men are packing 8 inches or more - and that's before you consider whether the person attached to it has anything to be attracted to.
So yes, there definitely are ridiculous women at the extreme end of the spectrum on this.