There are many other forms of preparation approved by the Catholic Church. We have just found this one to be the most effective. Well, actually, you decided on it by deciding to become a Sacrament. I'll try to not wax too theological. Catholics view the seven sacraments as a way of directly encountering Jesus.
Most people understand that it takes years of preparation to become a priest.
There is a lot of overlap in what the Catholic Church expects of a priest and a matrimonied couple. Most people do not think it takes any preparation to be married. The reality is, it takes a lot to be married, even more to become a sacrament. The forty four hours of the weekend just scratch the surface of what it really takes. It is a start.