If this question essentially boils down to "3-5 years of Jimmy Butler at age 28-30+ or 8-9+ years of Josh Jackson or Jayson Tatum at age 20-28," I think I would probably prefer to use the pick.
After all, we might be able to trade for Butler without including the 2017 Nets pick anyway.
Indeed! Don't sleep on Josh Jackson or Jonathan Isaac. They may be the players in this years draft! Keep the pick and sign a free agent!
During the claimed "3-5 years" of Jimmy Butler you are getting a guaranteed All-Star talent. The "8-9+ years" of Jackson/Tatum/Isaac sounds great if they end up being all-star level players, but a majority of top 5 picks don't get there. It's a gamble, but could pay off big if Danny drafts well. Trading for Jimmy puts us maybe at Clevelands level (if they keep playing like this), but we'd still be a star away from the Warriors level in my opinion, so maybe the "build for the future" route is best while we wait for GSW to cool off.
Decided to look at recent draft history to get an idea of how top 5 picks have turned out, here's what I came up with. Excluded 2013-2016 since the jury is still out on some of those guys.
Top 5 picks from 2004-2012 who made at least one All-Star Game
2004 - Dwight, Devin Harris (?)
2005 - Deron Williams, CP3
2006 - Aldridge
2007 - Durant, Horford
2008 - Rose, Westbrook, Love
2009 - Griffin, Harden
2010 - Wall, Cousins
2011 - Kyrie
2012 - Davis, Beal*
*Hasn't actually made it yet but he's an all star talent obviously
Anyways, that's just 17 out of 45 players or ~37.8%. Out of those 17, 6 of them were drafted #1 overall. Leaving Andrea Bargnani, Greg Oden & Andrew Bogut as the only #1 pick busts over that span. No suprise, but the odds of picking an all-star at #1 have been much better than 2-5.
Obviously though these drafts are all different in strength. This is supposed to be a stronger draft, so maybe it ends up like 2008 or 2003 (Lebrick, Darko, Melo, Bosh, Wade - though there isn't a Lebron level talent in this draft).