Anthony Davis is a good football player.
But the Niners trading up two spots to get him is bad for one simple reason: There was likely no reason for it.
While they only gave up a fourth-round pick (No. 113 overall) to move up, it seems like a pointless move. It's highly likely that Davis would've been available at No. 13, especially given that San Diego traded into the No. 12 spot—and neither Denver nor Miami needed an offensive lineman anyway.
So while it's a small, calculated risk to make sure they got their man, the Niners may not have really needed to take that risk at all.
And that's never worth any late-round pick.