In most families, there are times when what one person wants seems incompatible with what another wants. Rather than the parent self-sacrificing, or telling the child, however kindly, "life isn't fair", there are alternatives. The main investments required are time, creativity and flexibility.
For example, many children miss a parent who is at work all day. Is it possible for the child to go to the workplace too? Is it possible for the child and the person who cares for them during the day to make the commute to work with the parent, so they get some extra time together? Or come to the workplace to have coffee or lunch with the parent? Maybe there are good places to hang out near the workplace so the parent can pop out to touch base from time to time during the day.
I don't think we ever find a solution to balancing work/family that everyone is happy with for the foreseeable future. Families have to regularly recalibrate as their interests and activities change. A newborn baby might easily be welcomed in an open plan office in a sling, where they are at the mostly feeding and sleeping stage; a slightly older child might disturb colleagues less if the parent can have their own office, or take work home rather than sharing the office space.
I think families should try to find flexitime solutions wherever possible - being able to work while the child(ren) is/are happily occupied with something else, working at the weekends (which is often a great time for taking a child into an office) translates into four half-days during the week, making lists until the child's activities permit a whirlwind of ticking jobs off.