Once we understand that people have different ways of expressing their love and that other love languages may be less pronounced, this can massively improve our love life. Through this knowledge we become gain a better comprehension of the different languages of love. This also helps us better understand better why our partner's different expressions may differ from our own.
Even if a romantic relationship is mostly constant and somewhat happy for both sides, we often wish for an emotionally deeper bond. Especially in romantic partnerships, many of us want more intimacy, deeper understanding for one another, more passion and deeper conversations and thus more emotions and feelings.