In the upcoming Season 5 of Diablo 4, Blizzard has addressed numerous points of feedback that players have had with matters of Class balance and parity, material costs for Enchanting, and very notably: group play in The Pit of Artificers.
Diablo 4 Season 5 Patch 1.5.0 Patch Notes Now Available New Content Coming to Diablo 4 in Season 5
Previously, only the player who opened the Pit would receive the full amount of Masterworking materials.