It's highly unlikely that will you execute unnecessary queries from view code because usually you'll have a context like {"pizzas": page_obj.object_list}. You'll almost never execute something like:

  for pizza in pizzas:
      print(pizza.topping.name)

But you'll certainly do the following in templates:

  {% for pizza in pizzas %}
    <p>{{ pizza.topping.name }}</p>
  {% endfor %}

I also don't understand why you want to avoid 3rd party packages, especially if it helps you write better code.