Since you effectively channel it for the -2/-2 ability, its really hard for your opponents to stop you from interacting with their early board
Its certainly no Primeval Titan, but its still a big body with utility attached
They allow us to create dynamic change in a medium (printed cards) that pretty much is incapable of change
Also, Goldspan Dragon is a great pick if the deck is based not on Dragons, but on tokens and artifacts in general, with Treasures being great options for sacrificing permanents or putting lots of artifacts onto the battlefield at once
At higher Brackets, deck strength also depends on efficiency and commander choice
It still may not seem like much: The ability tries to transform the clone, but since it can't (because it's not a double-faced card), it just does nothing