Is it really a virtue to be useful to others?

“We must strive to be useful to others” or some variant of this message is often mentioned as a high virtue. But is it really a high virtue?

Does a rose bloom to be useful or does it bloom because that’s what it is and by being itself it automatically gives joy to those who find its fragrance beautiful.

Does a banyan tree intent to be useful to others or is it just being itself and people and animals find shade and shelter because of the natural roof it creates?

Is a cuckoo trying to be useful when it sings its song or is it just celebrating life and we join the celebration and enjoy its song?

I suspect that these wonderful creations of nature are just being themselves and it is humanity that derives the usefulness.