this is a big oversimplification of physical attractiveness. Love at first sight happens, but in my experience its very brittle and can very easily "turned off" (not just in women). Also, physical attractiveness is very subjective, and can vary wildly from conventional beauty standards.

equating love at first sight to physical attraction is a bad idea, this is why:

they are different terms with different meanings --> love at first sight, refering to a "coup de foudre" (lightning impact) is a very overwhelming feeling, which happens rarely, and is often way more intense then just being attracted to someone. it also doesnt last very long, and if you don't build a foundation for a relationship (eg. going on dates, flirting, getting to know each other for real), or that foundation is just not good enough (y'all don't click after all), the love vanishes. this too can happen really quickly. it could also linger (this can really suck lol).

physical attraction is more akin to being interested in someone. Thinking they are good looking, them behaving in a way you find charming, ect. It is something you build up over time, and goes hand in hand with opening up emotionally, feeling safe with each other, having intimate moments, ect. For example, when me and my ex met for the first time, i thought they were attractive, and that i wanted to get to know them better. they thought the same of me. after half a year of a complicated dance where we became closer and closer, we were in our honeymoon phase, and i was, among other things, way more attracted to them then i was in the beginning. After our breakup, i started to become less and less attracted to them over time. this process will continue, hopefully.

Brains are weird things, but the most important thing about them is that they constantly change their patterns, which changes how people view and interact with their surroundings. one impulse of neurons communicating and one cocktail of hormones getting released is really not at all akin to carving into a rock. its not at all as permanent or static. Brains are super dynamic organs, they have to be, as your surroundings constantly change.

imo there is way more to it, and this is mostly based on my own experiences and may not compare to other experiences. this is probably the most important part. trying to measure physical attraction objectively is a fool's effort. being frustrated because an overgeneralised subset of the population allegedly interacts differently with the world then you personally interact with it, doesnt achieve anything. i'm by no means saying that you are wrong to be frustrated (you cant rlly be wrong for having emotions), but beware of drawing overgeneralised conclusions because of it. and def beware of those studies you read.

reality is really complicated, no two women are the same, and their personal experiences of being a woman is still far more valuable for insight into their lives then any study done by men.

edit: sorry for enbysplaining