In a large skillet over medium heat, cook ground beef and onion until the beef is browned. Add garlic and cook for 1 minute. Drain excess grease.
Transfer the beef mixture to a 6-quart or larger slow cooker. Add potatoes, broth, Worcestershire sauce, salt, pepper, and smoked paprika. Stir to combine.
Cover and cook on low for 5 to 6 hours or on high for 3 to 4 hours, until potatoes are tender.
Whisk milk and cornstarch in a small bowl until smooth. Stir into the soup along with the cream cheese.
Cover and cook on high for 15 to 20 minutes, stirring once or twice, until the soup thickens and cream cheese melts.
Stir in shredded cheddar a handful at a time until melted. Do not boil the soup after adding cheese.
Taste and adjust seasoning. Serve with bacon, pickles, green onions, and extra cheddar if desired.