Most mistakes in beekeeping do not come from lack of care. They happen because the beekeeper does not have enough information at the right time.
The most common one is a delayed reaction to the end of nectar flow. Bees stop bringing in forage and start consuming stores, and the beekeeper finds out only at the next visit, which may have been two weeks later. Or feeding comes too late and the bees enter winter weaker than they could have.
The opposite problem is a missed nectar flow. A strong nectar flow sometimes lasts only a few days. If you do not come to the apiary in that period, supers are not added in time and part of the yield remains unused, not because you neglected the bees, but because you did not know that this was the right moment.
Unnecessary interventions are a less visible mistake, but a real one. The beekeeper comes to check when there is no reason, opens the hive, disturbs the bees and loses time. Every intervention has a cost, not only your time, but also the peace of the colony.
And then there is swarming. A sudden drop in weight in the graph is visible immediately. Without a scale, you notice it only at the next visit, when it is too late.
The scale will not eliminate these mistakes completely. But it greatly narrows the space where they can arise.