CMV: Platonic relationships, in general, are more loyal than romantic ones

Clarification: when I say platonic relationships I do not mean simple, typical friendship. Not someone who you hang out with every now and then and are cool. Essentially, they are as important as a romantic relationship without any sex and romance. So it takes love and as much dedication as a romantic one.

Romantic relationships are very conditional. It's essentially "You have sex with me and only me, otherwise I will break up with you and cut you out of my life." Which to me, seems shallow, very selfish and conditional. I think if you were truly loyal and loved someone, you'd still at the very least keep in touch. But the vast majority of failed relationships do not work. To love and spend time with a platonic girl as much as you would a girlfriend, to me that shows true and less conditional love and loyalty towards someone.

So why do you think romantic relationships are generally more loyal than platonic ones.