He is difficult to work with
wouldn't be surprised if Terminator:Dark Fate is his last film ever Reynolds and Cameron werent thriilled to work with him he is an Ass-Hole
https://www.cinemablend.com/news/2485519/deadpool-director-says-he-quit-because-ryan-reynolds-wanted-to-be-in-control
https://www.indiewire.com/2019/11/terminator-tim-miller-explains-bomb-james-cameron-creative-control-1202191988/