The term Work-Life Balance suggests a tradeoff between time spent on work and on life, with one borrowing from the other and a balance providing the silver bullet of happiness and contentedness. This is at least a little bit misleading, because while the tasks at work and home are different, how we feel at any moment in time is harder to compartmentalize to a certain part of the day.
What I've found more effective to strive for is better Task-Satisfaction Balance. If you don't enjoy what you're doing, it is much more likely because of the type of tasks you're doing, rather than because of the number of hours you're putting in. At work, doing the types of work you really enjoy are likely to help you do the work faster, whereas that which you find less enthusing or fulfilling consumes all time you have available. The is also true at home. To stop walking the path to burnout, I've found myself needing to catch myself spinning my wheels on mundane tasks and pivot fast.