Any kind of relationship requires emotional commitments on the part of all parties.   This is true no only for lover but also for friends.   If there is no emotional  commitment, then you are merely two known entities and nothing more.

But for lovers, emotional commitment is vital.  For the very act of committing is the act of giving your self to that other person unconditionally.  Without that emotional commitment, you are just a self centered parasites who are only using the other person for your own selfish needs.

And, without emotional commitment, love can never develop.