The C's post trade would absolutely be better than they are and much closer to a title, but right now I don't think they are better than Milwaukee, Brooklyn, or either LA and may not be better than Philly. So the questions are, (1) is when is Tatum going to take another big leap such that he ends up as a top 10ish player and (2) how long can Lillard stay at that level? I'm not sure the answer to either of those questions gives Boston a big enough or long enough window to make that trade.
So Roster post trade - Lillard, Smart, Tatum, Covington, Nurkic, Pritchard, Fournier, Langford, Nesmith, Ojeleye, Parker, G. Williams, Thompson, Kornet
That team is better than what we have, so I'd certainly think about it especially since Lillard is by a decent margin the best player in that trade. Covington and Nurkic are also solid contributing role players.