If he wanted to get out he could just get out. In hindsight I can't believe he was trying to do all this:
"With scripting duties and directing demands off his shoulders, Affleck will have more time to commit to overcoming the exhaustion and frustrations that became a problem for him recently after a demanding schedule that included Batman v Superman, Suicide Squad, The Accountant, Justice League, and Live By Night. Acting in all five of those films, plus doing scripting and editing duties on a few as well, and of course serving as writer-director-actor for Live By Night, put a strain on Affleck and made it difficult for him to focus on the screenplay for The Batman."