I think there are two things people tend to forget/undervalue. (1) Fit and (2) basketball value relative to their salary.
(1) With Joel Embiid and Ben Simmons as core players at the 4 and 5, our draft choices become more limited. We need players who can stretch the floor and have the mobility to defend at the perimeter. The top of the 2018 draft has some high upside, but the number of perimeter players is very limited. Mo Bamba, DeAndre Ayton, Marvin Bagley, Miles Bridges, Robert Williams, Wendell Carter, Nick Richardson and even Jarred Vanderbilt and Kevin Knox won't fit next to Embiid and Simmons.
So yeah, having a top 10 Lakers pick is valuable, but not as valuable as it is for other teams because of fit issues and I don't think that any of these prospects has a clear advantage over Embiid or Simmons. Luka Doncic and Collin Sexton are good fits, while Michael Porter might work due to his ability to stretch the floor (while he's also a 4, just like Simmons). The former and latter are probably not available with the Lakers pick and Sexton is a clear step down from Fultz imo.
Having a core of hopefully three max contract worthy players, who are a perfect fit in theory is insanely valuable.
(2) Another thing to keep in mind that 1 + 1 is not necessarily 2 in terms of basketball value.
Unbreakable99 wrote:3. Fultz must be better than the accumulation of Tatum AND whoever the Celtics get with our pick AND
For the sake of clarity let's use BPM as an indicator of a player's value and I'll try to explain why I disagree with the above statement.
In a dream outcome Fultz ends up at the best player of the draft, roughly a +4 BPM player. However, Jayson Tatum and let's say DeAndre Ayton end up fine as well, both +3 BPM players. Now a simple calculation would be that the combination of Tatum and Ayton is more valuable than Fultz, which is true, but not from a quality/salary standpoint.
The cap limitations in the NBA prevent truly great players from having a contract that is fair in comparison with their relative value on the court. This results in situations where LeBron James earns just a fraction more than perennial all-stars, that's why a truly great player is infinitely more valuable than a top ~25 player with a max contract.
With Embiid and Simmons as potential max caliber players, we don't have the room for multiple ~25% cap players.
Keeping both points in mind I think that Bryan Colangelo made the right decision, however this DOES NOT mean we "win" the trade. The Celtics are on a different timeline and want to win now while accumulating additional possibilities of drafting a future franchise player. Having two potentially top 5 picks increases the odds of drafting one. So from their perspective it makes sense as well.