I ended up falling in love with one of my best friends. And it’s true, I didn’t find him attractive at first. But because I’m demisexual I don’t really feel sexually attracted to people unless I have a strong relationship with them anyway. So as I got to know him more and more over the years it got to a point where suddenly a switch clicked and I suddenly found him attractive. And even then I felt more like “friends with benefits” until we’d spent more time together and discovered how much on a deeper level we connected, and eventually it was full “in love” feeling. It’s now been 7+ years of friendship and 3 years of love and it’s a beautiful thing. Because underneath the ups and downs of sexuality and romance there is always this firm bedrock of best friendship.
But I disagree that you want a best friend/boyfriend to not tell you when you’re crazy. I want my best friends, whether romantic or platonic, to be completely honest with me. That’s why they’re best friends. If I just want someone to gab with and shoot the sh*t with then that can be a casual friend, but a true best friend will tell you the truth. And so will a boyfriend, if he’s meant to be your long term partner.