A good work-life balance seems to be the epitome of healthy living. A concept introduced in the UK in the 1970s and in the mid-80s in the US as a concept including proper prioritizing between "work" (career and ambition) and "lifestyle" (health, pleasure, leisure, family and spiritual development/meditation)".(Wikipedia). Until the mid 19th. century this difference was unknown and work was life and life work. Then work became the bad part and life the good part of life. Retirement was invented and with it the notion that you would work hard and once you retire you would do what you "really" want to do (such as building your model railway) or die of a heart attack.
Any balance is inherently unstable. Also "work-life" indicates that work is in some way not life or the opposite of life (as in "get a life"). Yingzhao Liu also pointed this out in her talk on "Buddhist Alchemy: Transforming Everything into Wisdom" at Wisdom 2.0 - Integration is much more stable than balancing.
Maybe you think of the work and non-work parts of life. Yet however you turn it, as long as you don't accept everything you do as part of your life, you will always limit your presence - in your work and with your family and friends. Work and non-work. Free and non-free time. Possibly there are three or more parts: work - family - free.
As your friend: "So how was your weekend trip?" to hear "Life gets in the way - we didn't go, the kids were sick but soon ...". So life got in the way of your wish to be present. I banned this expression together with "whatever" as it distracts from being in the moment. It's an excuse for not addressing the issue at hand. Sailing the Bay on a beautiful day may have been more relaxing (albeit also colder) than tending to a sick child but was it as rewarding, as intimate? "I didn't want my life, I wanted to go sailing."
Balance scales measure weight, not mass - being the same on Earth and Mars - contrary to spring scales that show vastly different results when making a cake on Mars. If you ever used one, it is a tricky undertaking to get the known weights right.
Life cannot be measured in lbs and oz. as much as it cannot be measured in seconds or days.
Try it for yourself - do your best to be present, especially in tose "wasted moments" - in the bathroom, waiting for the printer, in the office, trying to get all kids into the car at the same time. Maybe you come home to be fully present with your family after a day in work where the moment when you experienced the blinking red light on the printer, indicating it's doing something internally that takes forever as the best part of your time in the office.