Think of it like dating in college.
ARKK = the girl with rapid mood swings. She's fun, energetic, and rowdy. She knows how to have a good time. She doesn't like labels or big commitments, but says she really likes you. Her mood is unpredictable, and when it's bad.....it's
really bad. Your friends and family express some concern about her, but the dopamine highs you get from her in the short-term are just too hard to walk away from. You have doubts about her ability to settle down and get married, but then again you start to think maybe marriage isn't all it's cracked up to be. Maybe you don't actually want to get married after all. Just when you begin to doubt yourself that maybe she isn't the right person, she professes to love you and states she doesn't know what she would do without you. You find her statements compelling and decide to stay with her, all the while ignoring the growing discomfort in your gut that this could end badly.
VTSAX = the college girl you see from across the library on Friday evening. She's calm, a little shy, very polite, and shockingly pretty. You strike up a conversation and are impressed by her intellect. She's strong in her values and exudes trust. She doesn't care to go out much on the weekends, and rowdy is hardly a word that would define her. You begin dating and find the process happens very naturally. Your friends and family adore her and ask that you invite her over whenever you come into town. You start thinking about marriage, and find yourself google-searching diamond rings in your downtime at work. While you maybe never saw it coming, you have no doubt that she is the one for you.
Hope that helps to clear things up. Which one do you really want to be with long-term?