You're right, but it is multiple things. These giant foods do lose flavor concentration. Additionally, a lot of these things are not allowed to ripen naturally. They are picked early and put in storage with nitrogen gas to suspend ripening. This is also why produce seems to spoil after 3 days in the fridge. You'll see quite a difference if you can get fresh grown vegetables from your own garden.

I think in the future, a lot of this produce will be grown at home in hydroponics devices. However, the bigger question there is figuring out the color of LED light to still produce a pleasing tomato.