LINQ: groupby and Join together

I need set of products per Category as shown below

Category: Electronics
  Laptop
  Monitor
Category: Peripherals
  Mouse
  Keyboard
Category: Furniture

where the data is given as a separate table for products and category

        List<Product> products = new List<Product>
        {
            new Product { ProductId = 1, Name = "Laptop",   Price = 1200m, CategoryId = 1 },
            new Product { ProductId = 2, Name = "Mouse",    Price = 25m,   CategoryId = 2 },
            new Product { ProductId = 3, Name = "Keyboard", Price = 75m,   CategoryId = 2 },
            new Product { ProductId = 4, Name = "Monitor",  Price = 300m,  CategoryId = 1 },
            new Product { ProductId = 5, Name = "Webcam",   Price = 50m,   CategoryId = 4 },
            new Product { ProductId = 6, Name = "Desk",     Price = 400m,  CategoryId = 3 }
        };
        List<Category> categories = new List<Category>
        {
            new Category { CategoryId = 1, Name = "Electronics" },
            new Category { CategoryId = 2, Name = "Peripherals" },
            new Category { CategoryId = 3, Name = "Furniture" }
        };

We can do it using Linq query as below

var result = (from c in categories
                join p in products on c.CategoryId equals p.CategoryId
                group new { c, p } by new { c.CategoryId, c.Name } into g
                select new
                {
                    CategoryId = g.Key.CategoryId,
                    CategoryName = g.Key.Name,
                    ProductNames = g.Select(x => x.p.Name).ToList()
                }).ToDictionary(x => x.CategoryName, x => x.ProductNames);

     foreach (var item in result)
     {
         Console.WriteLine($"Category: {item.Key}");
         foreach (var item2 in item.Value)
         {
              Console.WriteLine($"  {item2}");
         }
     }

Similarly, we can so this using Linq Method: GroupJoin

var result = categories.GroupJoin(
                products,
                category => category.CategoryId,
                product => product.CategoryId,
                (category, prodCollection) => new
                {
                    CategoryName = category.Name,
                    Products = prodCollection.Select(p => p.Name).ToList()
                });

     foreach (var item in result)
     {
          Console.WriteLine($"Category: {item.CategoryName}");
          foreach (var prod in item.Products)
          {
               Console.WriteLine($"  {prod}");
          }
     }