Bonehoard Dracosaur could see play in more casual or thematic decks, but competitive decks may opt for more powerful and reliable options
you don't exactly have a ton of targets you can send via its effect outside a lot of outdated Fusions (yeah, there's technically Sea Monster of Theseus now, but that one is better summoned off Instant Fusion to kickstart plays) and Vanilla Pendulums [which I guess helps to bypass the new rules].
Logistics is not only what happens at the venue, is the experience you provide since they register until the event is finished: making sure everything works
Gholdengo EX's attack does 50 damage times the amount of energy you discard from your hand, so if you use Energy Search Pro, you will instantly have 350 damage available from one item, which does not feel fair
With many fans looking back fondly of the Unovan region and it's unique Legendaries and Mythicals, this set was destined to shine