They should have went back in time and stopped Loki from pocketing the stone when he was in Odins treasure room.
Thanos attacked the Asgardian ship because Loki had the stone. But if the stone had been destroyed along with Hela, Surtur and Asgard it probably would have prevented less deaths. It also means Thanos wouldn't be able to snap. He wouldn't have all the stones.
Instead of going back in time and stopping Loki, they went back in time looking for dumb shyt like thor's old hammer that he didn't need anymore.
Thanos attacked the Asgardian ship because Loki had the stone. But if the stone had been destroyed along with Hela, Surtur and Asgard it probably would have prevented less deaths. It also means Thanos wouldn't be able to snap. He wouldn't have all the stones.
Instead of going back in time and stopping Loki, they went back in time looking for dumb shyt like thor's old hammer that he didn't need anymore.