The Los Angeles Lakers are certainly open to trading Lonzo Ball if a superstar becomes available. They'd drive him to the airport if they could pick up Anthony Davis in the same trip. But assuming a superstar isn't on the table, the Lakers have seemingly placed an emphasis on Ball's development in their coaching hire. They insisted on Jason Kidd joining the staff as an assistant so voraciously that Ty Lue turned down the job. While Kidd's relationship with LeBron James definitely played a role in his hiring, he has reportedly mentored Lonzo Ball in the past and the Lakers like the idea of having him in the building to work with their young point guard moving forward. The two are often compared to one another, after all.
So in a vacuum, a trade offer like the one that the Chicago Bulls are reportedly considering offering according to Joe Cowley of The Chicago Sun-Times just doesn't seem all that appealing. He reported earlier this week that, if the Bulls didn't finish with a top-two pick in the NBA Draft Lottery, they would be open to dealing their first-round choice to the Lakers in exchange for Ball. The Bulls came in at No. 7, so their interest would appear to be significant.
At the moment, the Lakers have no real reason to consider such a trade. They want to win right away. No rookie outside of Zion Williamson would realistically help them do so. Ball could. So if the Bulls wanted to make this trade straight up, and the Lakers had no ulterior motives with the pick, they would say no.