Cook and stir ground beef, onion, and garlic in a large skillet over medium-high heat until beef is completely browned; drain fat from the skillet.

Stir water and taco seasoning mix into beef mixture, then bring to a boil. Reduce the heat to medium-low and simmer, stirring occasionally, for 5 minutes.

Meanwhile, preheat the oven to 350 degrees F (175 degrees C). Place pizza crust onto a baking sheet.

Blend diced tomatoes, 1 cup salsa, and cilantro in a blender until smooth.

Spread refried beans in an even layer on the prepared pizza crust, leaving a border of about 1/2-inch uncovered around the outside. Spread 1 cup diced tomato mixture over beans in an even layer; reserve the remaining sauce. Scatter ground beef mixture over sauce, then cover with 1 1/2 cups cheese.

Bake in the preheated oven until cheese is bubbly and crust edges are golden brown, 15 to 20 minutes. Remove from the oven and let cool for 5 minutes.

Top pizza with shredded lettuce, chopped tomatoes, black olives, green onions, and remaining cheese. Serve with the reserved sauce, sour cream, and remaining salsa.