Keep in mind that sexual intent isn't a consideration.
I'd say that if you think of romance as something ephemeral or fleeting and of friendship as something grounded or permanent, then the two states can be reversed or interchangeable.
Then romance could be seen as chasing dreams while friendship pursues realism?
However we should also consider intent. Romantic feeling towards someone elevates them beyond the ordinary. It becomes a pursuit that gives out a part of oneself, in excess one might say. On the other hand, in order for friendship to reach that level of commitment or even higher, it's inevitable to pass through a stage of romantic idealization in the literary sense of the other person's attributes.
Complete intimacy means being a part of another's life and they being a part of yours. And to fully trust another in every aspect is something that can only be achieved through the idealistic view of romance.
If we were to joke about it... They don't call the intense, almost homoerotic friendship between men a bromance for nothing after all.
Sex was excluded from the theme and my thought was using that consideration.