Not necessarily. Prayer also brings forth grace, and good works, and study of the Holy Scripture. Besides, where did you get the idea that the Sacraments do not pour out the grace lavishly?
No Scripture to support that ANY sacraments impart ANY grace to the believer.
But to answer the question, if grace were imparted lavishly, it wouldn’t be lost every time we sinned and one would not have to go back for refills all the time.