Yes,when someone gets married after they loved for years,have to share sorrow and happiness between them and help themselves to get comfortable live with them but this is actually not happening other than few drama and movies.People will leae you when you are no more beneficial to them,its bit harsh but that the reality of modern day love.
That's not really a marriage should be. The things you see in drama and movies are quite exaggerated, tho there is some resemblance to reality it doesn't really portray what's the actuality. And some people take it as the truth--they believe it's the truth. Which is wrong in many ways.
The last part you mentioned sounds more like a contract than a marriage.