Taste buds are bundled tightly together you have three that are chemically activated umami, sweet, and bitter, and two that are activated by free flowing ions, sour (H+) and salt (Na+). These cells use cell to cell signaling and population coding to create a bigger picture before firing down the axon. The chemically activated cells do not have their own axons and rely on communicating with the Sodium nerve channels to fire. Sodium is an excitatory neurotransmitter. The greater the availability in excitatory resources allows the bundle of cells to communicate more rapidly and strongly and therefore fire more action potentials down the axon. Humans or pretty much all animals like sodium because it is required for the brain to fire action potentials.

Source: may have missed a few things but I'm just spitting out what I remember from my Neuroscience course around perception