I mean... trading Zach and Vuc wouldn't result in a complete tear down IMO because now the Bulls are in position to get at least neutral value back for them. It's not going to be a salary dump situation where a team gets them for nothing.
Hell, even with the MPJ for Zach trade, the Bulls are adding a 6'10 shooter to the roster and they already play at the fastest pace in the NBA.
Potentially slotting out a lineup of...
Giddey 6'8
Coby 6'5
MPJ 6'10
Pat 6'8
Jalen 6'10
All those guys will be spacing the floor like crazy, then you still have Ayo, Matas, Lonzo, Julian, Dalen, THT... players that play hard af and are hungry. They wouldn't just be rolling the balls out there taking Ls. That's a young team with guys who have started for playoff teams, 1 NBA champion and a lot of other parts that are competent.
I don't know what they get back for Vuc, but regardless, they waited entirely too long to pivot now.