That's pretty much Joseph's floor. His ceiling could be a 35-40 HR, .900 OPS 1B, given his lack of experience, he certainly has the potential to be a lot better than he's shown so far.
Conversely, any draft pick has a flop potential that's higher than a player who's already gone through the minors or has had ML success.
So for Smith to be comparable to Joseph or Hoskins, his ceiling has to be above theirs, since his floor is below their floors.
Now if Smith is clearly the BPA, that doesn't matter, but there's no evidence that he's substantially better than the players who will be available around him.
And to the Phillies, his value is less b/c they have so many organizational options at 1B (Randolph for example, who's probably has a similar ceiling as a hitter).
So they may be better off with a riskier pick like Beck, who would be more tradeable if he makes it, than a more certain player who'd have limited trade value and be blocked.