Winter is a strange period for a beekeeper. The hives are closed, the bees do not move and you have no way to know what is happening inside without disturbing wintering. The scale reduces this blind spot.
A healthy colony in winter slowly and evenly consumes stores. In the graph, it looks like a mild regular decline, a few tens of grams per day, sometimes even less. If the decline suddenly speeds up, something has changed. Stores are disappearing faster than they should.
The opposite signal is just as important. If weight does not fall at all, the colony may have died. A living colony always consumes, even if only a little. A motionless graph in January or February is a reason to look more closely.
In spring, when temperatures begin to change, store consumption starts to rise. Bees wake up, brood rearing starts and needs grow. This is exactly the period when spring starvation is a risk: stores are running out and nectar flow has not started yet. The scale shows when the decline is accelerating and when it is time to add feed without opening the hive in the cold.
Most problems during wintering are discovered too late, only when you come in spring and it is already over. The scale does not answer everything, but it gives you time to react.