If a creature is flying/aloft via an object not directly related to them (flying on a magic broom, a flying carpet, or similar, with the creature having no flying speed themselves), can Earthbind target them causing them to descend? Earthbind only affects the creature's flying speed.

If the item they're using has its own flying speed, like a flying carpet, the carpet isn't affected.

— Dan Dillon (@Dan_Dillon_1) July 12, 2020