Not how they are grown, but when they were harvested.

Ripe tomatoes are more delicate than underdeveloped, still green tomatoes. So pick them before done developing, ship them, and they'll turn red in the weeks it takes to get to the store.

And if they are picked ripe, they'll also go bad before they even get to shelf via their weeks long boat journey.

That's why local is better, and your own garden better still.