So it's not the easiest thing to gather and organize your thoughts on this complex trade, especially without emotion. At first when I saw the Nets pick was included, and that it was unprotected, I was pretty peeved. But here is how I would talk you off the ledge:
1) This trade tells me that IT was going to take whoever was going to give him a max, and Danny wasn't going to give it to him. So I'm going to consider that IT was gone for nothing at the end of the year, and we weren't winning it all with him this year, so for effective purposes I'd remove him from the deal. You don't have to agree here, but that's my view.
2) With IT factored out, the trade is really 2 role players and a lottery pick for a top 15 player in the NBA. So far that's a good deal for us, but it will come down to where the pick lands. If it lands top 2, or even top 5, that'll be tough to swallow. But if the Bulls, Pacers, Hawks and 2 West teams finish worse and the Nets finish out of the bottom 5 (say #6) and on lottery night they drop another spot or two (say pick #7 or #8) then I think that could be a steal.
3) IT may be damaged goods now and may have peaked, or will have peaked after 1-2 more years. Tatum & Jaylen likely won't be in their primes then. Kyrie likely gets better than he is now, and likely has a bigger year than IT this year if their roles were reversed since he played with Lebron and Love. Now, both of our top 2 players / all stars are on the timeline of the future of our team, which is Tatum, JB, LA/SAC pick, and the rest.
4) Re: timeline, with the Warriors being what they are we needed to stop straddling the line between the present and the future at some point. If we stayed the course we could have been a top 5 team for over a decade, but likely never would have been a true contender. Now if the LA pick lands and we nail it, and our young guys develop, we are likely to be a true contender in 3-4 years when the young guys develop and Kyrie is in his prime.
5) With the money we save next year due to the trade, we should be able to afford to keep Smart if that's what we want to do. If he doesn't develop good offense next season he should be affordable under the tax, and if he does, he'd be a player worth getting taxed for.
So factoring out IT and looking at the trade as 2 role players and a lottery pick for a top 15 player and cap flexibility, we need to wait a year and see where the pick lands. Even if the pick is top 2, which seems bad, we'd need to wait to see who pans out.