I have carved several thousand gunning and decorative decoys I use basswood because of availability to me. It is a junk wood to burn and I can get it for free. All of my hunting decoys are hollowed out to get them to float correctly and cut down on weight.
I can get all the white cedar I would ever need for free on my land but there is a lot of waste because of pin knots that you would need to fill with plugs to get a smooth water tight surface. It also takes 75-100 years to grow a white cedar to to a size that you can get a block from it. The trees make a better winter cover for the deer than a decoy.
For a competition decorative decoys I use tupelo because it holds finer details better. If tupelo was a cheap local wood I would use it all the time. My source for tupelo is in Louisiana.