Taste is one thing, the nutrient content also differs. In dairy and meat the fatty acid profile is different based on the animals feed and breed, in vegetables it depends on the plants growing conditions and variety.
Modern varieties optimize for simple KPIs, but lack nutrients. A modern grocery store tomate will have the same amount of nutrients as a smaller older variety, but since the older variety is smaller you will end up eating more tomatoes and have a more nutritious diet.
Most people just don't care. Food is energy and it needs to be cheap. Worrying about taste is a privileged concern. It's for most people, "good enough".
Modern varieties optimize for simple KPIs, but lack nutrients. A modern grocery store tomate will have the same amount of nutrients as a smaller older variety, but since the older variety is smaller you will end up eating more tomatoes and have a more nutritious diet.