Are Ukraine drones really exposing gaps in Russia's defense?

Are Ukraine drones really exposing gaps in Russia's defense? DW.com No fuel, no weapons: How Ukraine’s new drone strategy is mauling Russian supply lines CNN Ukraine war briefing: Drones strike Russia’s Tyumen oil refinery 2,000km away, says Zelenskyy The Guardian Moscow Refinery Blast May Have Been Caused by Friendly Fire, Video Suggests The New York Times Moscow residents complain of black rain after largest Ukrainian attack hits oil refinery BBC