Here are some reasons why Ebenezer Scrooge, the "squeezing, wrenching, grasping, scraping, clutching, covetous old sinner" of Charles Dickens's Christmas novella, A Christmas Carol, might have cause to be envious of the Cratchit family.
Bob Cratchit is happily married. Bob is married to Mrs. Cratchit (who has no first name in Dickens's novella, but is called Emily in some later adaptations), a patient, kindly, understanding woman who loves Bob and cares for him and their family.
Scrooge has no wife to love and care for him. He rejected that possibility when he chose the pursuit of money over Belle, the woman to whom he was betrothed when he was a young man.
"Another idol has displaced me..."
“What Idol has displaced you?” he rejoined.
“A golden one. ... I have seen your nobler aspirations fall off one by one, until the master-passion, Gain, engrosses you." (Stave Two)
The Cratchits have a large, happy, loving family. There's Martha, home from her job in the city to be with the family at Christmas; Belinda; Peter; two smaller children; and the youngest, Tiny Tim.
Bob and the family enjoy each other, and they enjoy what little they have. Bob spends his meagre salary on his family, for the goose for Christmas dinner and for presents for his wife and children.
Scrooge spends none of his money on anybody, including himself. His home is dark and cold, but "darkness is cheap, and Scrooge liked it." He has little to eat and spends little to warm himself.
[A] small fire in the grate; spoon and basin ready; and the little saucepan of gruel (Scrooge had a cold in his head) upon the hob. (Stave One)
Scrooge has no family life. There's no mention of Scrooge's mother in the story. Scrooge was raised by his father, a cold, distant man who sent Ebenezer off to boarding school when he was a young boy. Scrooge's father took little interest in him, and didn't even visit him at Christmastime.
Scrooge's sister, Fan, loved him dearly and appeared at the boarding school one Christmas to take Ebenezer home.
[A] little girl, much younger than the boy, came darting in, and putting her arms about his neck, and often kissing him, addressed him as her “Dear, dear brother.”...
“She died a woman,” said the Ghost, “and had, as I think, children.”
“One child,” Scrooge returned.
“True,” said the Ghost. “Your nephew!” (Stave Two)
Scrooge is annoyed by his nephew, Fred (Fan's son), and rejects Fred's invitation to Christmas dinner. Scrooge can't understand why Fred married for love. Scrooge thinks that Fred is frivolous, and Scrooge can't understand why Fred doesn't pursue money with the same vigor and ardor that he does.
The Cratchits have a spiritual life. The Cratchits attend church services, and they enjoy interacting with other churchgoers.
They also lead full and richly spiritual lives. They understand and accept their circumstances in life, and they work together, unselfishly, to make life better and more fulfilling for each other.
Scrooge has no spiritual life. He comes to realize how empty his life has been when he's faced with his own death in Stave Four.
“Spirit!” he cried, tight clutching at its robe, “hear me! I am not the man I was. I will not be the man I must have been but for this intercourse. Why show me this if I am past all hope?”
"...Assure me that I yet may change these shadows you have shown me by an altered life!..."
"I will honour Christmas in my heart, and try to keep it all the year. I will live in the Past, the Present, and the Future. The Spirits of all Three shall strive within me. I will not shut out the lessons that they teach."
By the end of the novella, Scrooge no longer has any reason to be envious of the Cratchits, because he now embraces everything that the Cratchits represent.