In my experience there are three kinds of people in relationships, and we might go through a couple or all of the stages in our lifetime:

1. The really bad ones. So bad they don't even deserve to be in relationships. They yell, they hit, they cheat, they lie, manipulate and/or all sorts of other things. 

They probably have deep rooted problems of showing respect to other people. They didn't get any while growing up, they saw their parents having a really dysfunctional relationship. Whatever it was, they didn't get past it, and haven't yet grown into a full adult. They might look like one, but their raging inner child still controls them.

Unless they decide to change radically and work on themselves for a looooong period of time, I don't think they'll ever reach at least level 2.

They can feel like a safe place if you got a pattern for an abusive relationship. If you choose people like that it's overdue time to do some work on yourself as well.

2. The bare minimum ones. It's not that bad to be with them but it's not that good either. They do enough to keep the relationship going, you occasionally spend a good time, but they don't really address your needs/love languages or do the necessary work to change their negative character traits. 

They don't really work on themselves, they push their unsolved issues deep within them and hope everything will work out, take love and the relationship for granted and don't "feed" it attention and affection so it can nourish. They can be passive aggressive as they can't communicate well. And they "activate" and try to be a good partner only when the relationships goes down hill.

They probably invest their energy in something else and/or are not aware that relationships involve more work in order to be successful. If only they would put more of their energy into the relationship, try to get better at being a good partner on a daily basis, they might move on to level 3.

They can feel like a safe place in the beginning, as some pretend to be a good partner at the start of the relationship, or if you don't like putting too much effort in a relationship either.

3. The high performing ones. The ones that actually enjoy working at the relationship. Who take the necessary steps to change and grow, to make the relationship stronger and more beautiful.

They probably have read hundreds of pages about what it takes to be a good partner, or have done dozens of therapy hours. They have prepared for a good relationship. They are not perfect, but they are willing to do hard work on themselves, open up an be vulnerable, own up to their mistakes and try to be better every day.

They have healthy ways of dealing with anger, communicating their wishes, setting boundaries. They understand their love language might be different from their partner's and find ways to show their love in the best way it can reach the other person.

They might not feel like a safe place in the beginning if you were used to being treated poorly. But they will heal you in time.

The third ones are very rare, especially men, that's why I married my partner as soon as I found him :)