Cook the fettuccine pasta in a large pot of salted boiling water until al dente, about 8 to 10 minutes. Drain and set aside.
In a large skillet, cook the chopped bacon over medium heat until crispy, about 5 to 7 minutes. Remove and drain on paper towels, keeping the drippings in the skillet.
Sauté the ground beef in the same skillet with bacon drippings, seasoning with garlic powder, onion powder, salt, and pepper, until browned, about 6 to 8 minutes.
Add heavy cream to the skillet with the beef, stirring to combine. Then add cheddar and Parmesan cheese, cooking over low heat until melted and thickened, about 5 to 7 minutes.
Combine the cooked fettuccine with the Alfredo sauce, tossing to coat. Stir in the crispy bacon, green onions, and diced tomatoes.
Serve immediately, garnished with extra cheese or green onions if desired.