In my experience, no.
Not good ones.
Your relationship with your best friends are not hard work, right? Why would it be hard work for someone you’re expecting to love? To spend the rest of your life with?
Sure, there are going to be times when you have to work at it.
To learn.
To grow.
To stretch yourself.
But hard work?
To me, if a relationship is hard work, it’s not working. It’s not good.