"Destroy" effects are far from the most reliable removal in a format like Modern, but there's a lot to be said for any card that replaces itself, especially at this cheap a cost
Sure his power level is good enough for the cube but with the competition for slots it is unwise to waste them on narrower gold cards that offer little more than good value
From a competitive standpoint, not many of these see much play, although Ketramose, the New Dawn is the face of a hot new Modern combo deck
Have other creatures with myriad in the build to increase how many tokens you create
Currently, The Soul Stone is easily the most expensive MTG Spider Man card, and its not even close
Pantlaza's Discover ability means that each dinosaur you cast has the potential to trigger a cascade, letting you fetch up one or potentially more other random dinosaurs from your deck (worst case scenario you hit a mana rock or something)