Seed Varieties, Where did they all go?

As you can see in this infogram plant varieties have reduced greatly after the modernization of seed catalogs. This is caused by a few reasons, the main two are the big commercial growers have a hard time controlling that much stock, and the second is the backyard grower who passed down seeds from generations are not around anymore. Luckily for us there has been a rise in the number of farmers who specialize in the unique but that's a different topic. So the question is asked why is it better to have many varieties then just a few that do ok everywhere? Customization! Years ago if you were in New England you found seeds that grew really well for where you are, and if you went down south you had a hard time finding those varieties, they had something similar but were better suited for their region.  Take for example the Connecticut pumpkin, the Kentucky wonder bush bean, the Boston pickling cucumber. Each in their region great crops, but outside of it there were less than average.  So now we are left with what big growers picking and choosing for us what's available. These companies select seeds based on its ability to produce beautiful fruit not as much on taste or region specific traits. So how do we prevent this from happening?  Start saving your own seeds.  Talk to the local nursery see if they know of see swaps in your area, maybe someone there has a variety of vegetables you remember from when you were a kid but you thought they were lost.  And most importantly encourage someone to garden. If all of my followers were to share what they know with just their neighbor we could save those loss seeds.