Today's Sweeper event lasted 1h15! People get tired and just leave, and since it doesn't end until a certain % has been mined, it takes even longer. It should have a time limit. The blocks are no longer insta-mined, we don't get the blocks we mine like last season, there's barely any incentive for people to even join it, so the few who do are stuck there for an hour.
I also earned over 6k mana from mining those damn blocks, it took so long! Please!