Russia, presumably, has exhausted its stock of Iranian kamikaze drones, so it will look for ways to replenish them.
The British Ministry of Defense writes about this with reference to intelligence data. They recalled that since around February 15, 2023, there have been no reports of the use of Iranian kamikaze drones in Ukraine.
Prior to this, the Ukrainian armed forces reported downing at least 24 Shahed-136 UAVs from late January to early February 2023. Dozens more were destroyed in the first few days of the year.
"Although this weapon does not perform well in destroying targets, Russia probably sees it as a useful decoy that can divert Ukrainian air defenses from more effective Russian cruise missiles," British intelligence said.