The Jazz Aren't Ready to Win Now
As currently constructed, and with no major free agency moves, the Jazz have made it clear they have no intention to build around Markkanen or try to win games now. Allowing Markkanen to win games and then walk at the end of the season does your team zero favors in the long-term, so offloading him either now or at the trade deadline makes the most sense if they don't want to re-sign him.
If the Jazz wanted Markkanen to be part of their core, he would have already signed a contract extension. If the Jazz truly want to get the best lottery odds in the 2025 draft, they need to move Lauri before the season begins.