Hi Maryl!
When it comes to the cut flower trade, I think dahlias are used most for weddings and funerals. They don't last super long, like ornery carnations and roses do. There are many varieties that are fantastic cut flowers. I grow for my own love of dahlias, but do sell to florists and random people, usually it is for weddings or special events. They will probably never have a fragrance, other than the one I glean when I cut the stem.
Kudos to you for trying once upon a time in Oklahoma. I live/grow in Nebraska, which is a little kinder, but dang that humidity...