I will have to accept on the other hand that in some aspects, singledom is better than marriage, especially when it comes to freedom. However, it should be also known that freedom alone can NOT make a person happy. When you have too much of it, life just becomes very predictable and as such, it becomes boring. There are things you need more than freedom to be satisfied with life.
But anyway, I would still say that the ups of married life outnumber the ups of single life. Also, the statement that "marriage is hard" is very skewed. Marriage in itself is not hard or easy, it is just a life stage. What makes it more or less difficult and stressful are the own spouses. Most of the problems dont simply appear, but are created by either one or both of the parties. The reason most married people are unsatisfied with their marriages, is because in all of them there is atleast one spouse who is not material for a marriage.