Usefulness is not a feature list. It is whether a thing earns its place in someone's day — whether it makes a difficult thing possible, or a possible thing worthwhile.
Most software is impressive. Very little of it is useful in this stricter sense. The industry rewards shipment. Artha is interested in the quieter test: would the world be worse if this did not exist?
That test is unfashionable. It is also the only one that compounds.