Keaton exited the franchise after Batman Returns and Burton was replaced in the director’s chair by Joel Schumacher, with Val Kilmer taking on the title role.
I knew it was in trouble when he [Joel Schumacher] said ‘Why does everything have to be so dark?’”
Before Christopher Nolan and Christian Bale got their hands on the Batman franchise and revolutionized it into a realistic and gritty cinematic behemoth with The Dark Knight trilogy, Batman movies were vastly different entities.
Happily, Keaton still has fond memories of his time as Bruce Wayne, specifically working with Tim Burton who he calls “an artist and a visionary” in a same interview.