I don't think a man can be friends with a hot girl and not want anything to happen. You can tell straight away when you see someone if you find them attractive or not. If you become friends with them nothing changes. You are still attracted to them.
If a man saw a girl and weren't attracted to them and then became friends. It might be he never becomes attracted to her. Though she could have been attracted to him all along.
I think it would be very rare for friendships between man and woman to be completely platonic. One side will often be attracted to the other or have fantasized about doing the do with them and would be up for doing the do with them, and I think particularly the male side.
I see your point but I don't fuuuully agree.
Growing up as bi, I always found this a strange topic. For me it's not so much only the opposite sex that I could be attracted to, and so graduately I've stopped seeing the opposite sex as only in the glasses of sexual appeal. I feel that many men tend to primarily look to other men for potential friends and to every other girl as potential lovers. If I would do that being bi, I would have 0 friends... From my perspective, I think this is therefore a bit of a cultural thing. I understand it. When you grow up girls are seen as more mysterious (and they think the same about guys). Especially for younger ages girls tend to hang out more with girls and guys also with other guys. Most people have more in common with people from their own gender so that's why they hang out more with their own gender than with the opposite gender. And when you're looking for a potential lover you're not gonna waste your time in making 100s of friendships with the opposite sex. And so of course you'd be curious when an attractive person of the other sex would approach you, are they perhaps interested in you, could they be a potential partner?
But yeah, like I said, if I would have that mentality than I would be unable to develop deep friendships with almost anyone. What I developed instead are 2 simple things that define for me the difference between potential lovers and other people: different from what you might expect I actually became more picky. I have specific types. You either are my type or you're not. You can be very attractive but if you're not my type I'm not that interested. And I almost never fall in love with friends. For me friends feel like "my own gender" xD
If someone is completely my type then no, I just cannot be friends, there will always be more between us. Sometimes people are on the edge, in certain circumstances something could happen and in others not. In this case it just depends how it starts. My current best friend is a girl and she is freaking hot. She's always been this "she miiight be my type" kind of person, an being so attractive in the beginning that did play a role. But due to circumstances it never really developed, we started to hang out around the same time that she got her current boyfriend. So it was never that much of an option to pursue it anyway. And since we met I've had huge crushes on other people myself that completely overshadowed my attraction to her. Nowadays that attraction mostly disappeared, it feels weird to think about her in a sexual way. But that's because she is such a good friend, it feels more like she is a sibling, and being attracted to her would thus feel a bit incestual...
I do think there is a difference between having male and female friends. That is because you don't assume a guy is/can be attracted to you. When you get close that never comes up in your mind. And the same for me. Even if I would still find him somewhat attractive, I would never see him in such a light because I assume that's not even a possibility. Therefore I find it more easy to make male friends. When I befriend a girl, not only is there that question whether I could be attracted to her, but also what she thinks about me. And when we get closer the question of what I mean to her is always on my mind.
tl;dr: But yeah, i think platonic friendships definitely exist. I have plenty of them (male and female). But I do understand why people would doubt their feasibility, and I think that's mostly a cultural thing. If you're in love with someone you won't be able to platonically befriend them. And even if you're not in love with them, under the right circumstances you probably always can fall in love though. And many guys pretty much allow this to happen I think, what makes having guy-girl friendships difficult. For me I constructed my own limits, and so I probably just don't allow a lot of romance and sexual interest to happen. And so for those who fall outside of my limits our friendships are pretty platonic.