What do you call someone who’s the opposite of a workaholic but isn’t lazy?

I would call them “normal”. Or someone who has figured out how to have a balanced life. That’s the goal.

Obviously, workaholism and laziness are at the extreme ends of human production. The goal is to be in the middle somewhere, where you are feeling helpful and productive, but not so much that you end up exhausted and burnt out because you aren’t taking care of yourself.

That is pretty much the definition of a balanced life: a healthy balance between laziness and workaholism. As well as a balance between work and other aspects of life such as health, relationships, friends, hobbies, etc.