“The Trunk, Leaves, and Flowers of this Tree, very much resemble
those of the Orange-tree.
The Fruit, when ripe, is something longer and larger than the largest
Orange; and exceeds, in the Delicacy of its Taste, the Fruit of every
Tree in this or any of our neighbouring Islands.
It hath somewhat of the Taste of a Shaddock (Pomelo); but far exceeds that, as
well as the best Orange, in its delicious Taste and Flavour.”

—Description from Hughes’ 1750 Natural History of Barbados.  (Wiki)
The grapefruit is the hybrid of a Jamaican Sweet Orange and an Indonesian Pomelo, which blended together either via intentional or accidental efforts of explorers.  Citrus sinensis x Citrus maximus combined to form a tasty treat that runs from the sweet to the sour. These days one has to be careful with grapefruit as it has the ability to block the absorption of some drugs.
But, beyond that, this grapefruit and several others were a tasty, sweet treat, picked off trees in Palm Desert. Most of us do not get enough fruit, and particularly citrus fruit, in our diets.